After a couple of years of struggling with email I have finally found the solution to make sure each of my emails reaches the inbox of its recipient and I'm about to share it with you.

Note: this is not a paid review. In fact, since Postmark doesn't have an affiliate program, it's not even a post with some affiliate links. It's just me solving a problem for myself that I hope you will now be able to solve too.

The problem: email not reaching its recipient

I wrote about email reliability before, but let's be honest: getting all the web servers we use for sites to send email reliably is a pain. You need to setup SPF records, preferably set up DKIM too and make sure that your web servers do not get blacklisted. One of my servers, for which I had set up SPF, for some stupid reason got blacklisted a couple of weeks ago, resulting in a couple of website review emails not reaching my customers. I hated that so much that I started looking for another solution.

On this site, I had switched from Gravity Forms to Wufoo a while back. Wufoo is another awesome web forms service, with the at that time "added value" that Wufoo would take care of the email sending for me. My main gripe with using Wufoo was that I really wanted my forms and the entries of my forms in my site's install, not somewhere else. On top of that, Gravity Forms gives me a bit more programming flexibility, so I wanted it back. So, I had two email problems and started to look for a solution to both at the same time.

Postmark: reliable email

I found that solution in Postmark, which handles transactional email through a set of reasonably simple but reliable API's. Using this pre-built library, I was able to replace the email sending in my website review application for Postmark within about 10 minutes.

Yes, Postmark costs a bit of money, but if you consider that at $1,50 per thousand emails, you run a lot smaller chance of losing customers over email not reaching its destination, it seems to me that that's money well-spent.

It took me a bit longer to code a WordPress plugin that I liked for Postmark. There are a couple of WordPress plugins listed on the Postmark site, but all of them relied on CURL, which I don't have on every server I run WordPress on, and they all ignored some of the headers that plugins like Gravity Forms passed along. So I used the same pre-built library, but adapted it this time to use the WordPress HTTP libraries and added a wrapper to more reliably pick up all the headers that might get added by plugins.

The result is a plugin that is pretty easy to use, my own Postmark Email for WordPress Plugin.

WordPress email sending tips

By default, WordPress sends email from wordpress@example.com, where example.com is your domain. In 99% of cases this is a non-existing email address. More and more people, including Postmark, are saying that using a non-existent email to send your email from is not a good idea. I agree. So I created wordpress@yoast.com, which gets filtered into a tag in my email.

The great thing about actually creating that email address is that you can also assign a gravatar to it. This means that when people use email clients like Sparrow, or other email clients that support Gravatar, they'll see a nice avatar image for your email too. In my case, I made sure that image was the Yoast logo.

Go forth and email!

And please do let me know your comments about both Postmark, the plugin and your tips for reliable email in the comments!

Sending Reliable Email with Postmark is a post by Joost de Valk on Yoast - Tweaking Websites.A good WordPress blog needs good hosting, you don't want your blog to be slow, or, even worse, down, do you? Check out my thoughts on WordPress hosting!

There's all sorts of factors that decide on whether your email is delivered or not, but one of the most important ones is a DNS record called SPF. SPF stands for Sender Policy Framework and let's the receiving mail server reliably determine whether the server that is sending you email is actually allowed to send you email. Adding one will increase your email reliability incredibly.

As with most DNS type records, the syntax is quite hard to explain so I won't even try. Let me link you to the Wikipedia page if you really want to know. What I found way more helpful though when I was searching and trying to figure out how to do this is Microsoft's wizard for this stuff. It asks you a bunch of questions and will still require some time from your side but it got me to the desired end-result a lot faster.

SPF records, Google Apps for Domain and email reliability

I use Google Apps for domain to handle my email, which means that I do most of my sending through a Google SMTP server. Because of that I had set the SPF record in the manner Google suggests here. The thing missing from that is very, very subtle, but makes all the difference. It's a few letters, let's see if you can spot it. This is the SPF record Google gave me:

v=spf1 include:_spf.google.com ~all

This is what it actually needed to be:

v=spf1 a include:_spf.google.com ~all

You will have spotted the addition of "a " after "spf1". This simple addition means that all web servers that are identified in my domains A records, hence, all the web servers from which I run my domain and subdomains, are allowed to send email as well.

The include directive means that Google can setup SPF records for the domain _spf.google.com and thus add or remove mail servers without you having to change anything.

How to test email reliability

If you're now thinking "I don't know whether this has been set up correctly for my domain", don't fret. You can test it quite easily. Go to this SPF testing tool and use the 3rd form on the page. Using only the first and third input of that form, enter your web server's IP address and your from address, which is usually wordpress@yourdomain.com if you're running WordPress. With my initial test, it gave this result:

This means that this test won't fail your email per se (as there was no SPF record), but for stricter email servers, it might, in other words, you've got quite low email reliability. Now I ran it with the SPF record I has just fashioned using Microsoft's wizard and it gave me this:

That is the result you want to see, as that means my server's email reliability just went up quite a bit.

WordPress specific email reliability: using another SMTP server

Quite often email from your own server won't work as expected, especially when you're on a shared host it can give issues. There are quite a few plugins out there to help you set up an external SMTP server, I've relied on Coffee2Code's Configure SMTP plugin myself a few times. There's some issues with that though, especially once you're starting to get more visitors, as most SMTP servers for free email services have a limit to how many emails you can send per day.

If you can, just use your own server or outsource the email delivery to a third party that specializes in sending service emails. I've been testing SendGrid myself, but wasn't completely happy with it. Their reliability was a lot higher but the costs are quite high too when you get several hundreds of comments. You might think "that's only a couple of hundred emails", well, it's not.

If you have subscribe to comments enabled, which I highly suggest you do, it'll be a lot more. I get anywhere from 20 to 200 comments on a post, average about 80 at the moment. If 50% subscribes to comment notifications, that adds up to an enormous amount of email being sent.

As for newsletters, there are plugins for sending those from your WordPress install too. I highly encourage you not to do that. Use Mailchimp, or any other newsletter service for that. Their reliability is way higher and you get awesome statistics and subscription services to boot. I use them for my WordPress Newsletter and never regret it.

Are you using other services that send email for you?

If you're using other services that send email for you, for instance if you're using Freshbooks (aff) for invoicing like I do, be sure to include them in your SPF too, just add another include like we did above for Google:

include:_spf.freshbooks.com

There are more services that support this, be sure to check if you're using any services that send email on your behalf. Email reliability is important, but even more important when it's sending your invoices!

Update from Antonio Romero in the comments, the same goes for MailChimp:

include:servers.mcsv.net

Just updated my own SPF with that as I use my own email address as a from address there.

Conclusion: make sure your email reliability is high!

Whether you run your own server or not, it can't hurt to do the check above to see whether your email has a high chance of being delivered. If you're sending email from your web server, be sure to do the above check and make the necessary changes to your SPF record if needed!

Bonus tip: DKIM

If you're using Google Apps for domain, be sure to read this guide and implement everything in it. It'll help you set up domain keys, which adds another layer of spam protection.

Email Reliability: use an SPF record is a post by Joost de Valk on Yoast - Tweaking Websites.A good WordPress blog needs good hosting, you don't want your blog to be slow, or, even worse, down, do you? Check out my thoughts on WordPress hosting!

This isn't for the faint of heart, if you're not a programmer this might be a bit tough to do, but I'll outline how it works:

Adding a comment meta value

Using the reasonably new comment_meta API, we're gonna add a piece of data to comments, that stores whether people want to subscribe to the newsletter or not. I did that by adding the following function to my functions.php file:

function ymc_add_meta_settings($comment_id) {
  add_comment_meta(
    $comment_id,
    'mailchimp_subscribe',
    $_POST['mailchimp_subscribe'],
    true
  );
}
add_action ('comment_post', 'ymc_add_meta_settings', 1);

Add a checkbox to the comment form

That wasn't too hard yet right? Next we add the checkbox to the comment form, wherever that is located in your theme, it's just plain (X)HTML:

<input type="checkbox" name="mailchimp_subscribe"
  id="mailchimp_subscribe"/>
<label for="mailchimp_subscribe">
  Subscribe to Yoast WordPress Newsletter (weekly email)
</label>

Subscribe the commenter

That's not really rocket science either. The next step is to take this data and work it. What we'll do is use the Mailchimp API to automatically subscribe people, and send them a confirmation email (we still need to make sure they double-opt-in).

First, let's grab the comment:

function ymc_subscription_add( $cid, $comment ) {
  $cid = (int) $cid;

  if ( !is_object($comment) )
    $comment = get_comment($cid);

  if ( $comment->comment_karma == 0 ) {
    // DO WORK
  }
}
add_action('comment_approved_','ymc_subscription_add',10,1);
add_action('comment_post', 'ymc_subscription_add', 60,1);

The code above makes sure we only do anything with comments that have been approved. So if a comment is approved as spam, it gets ignored. It also makes sure the $comment variable is filled with the comment. Now once we've done this, we're going to check whether the commenter wanted to be subscribed to the newsletter, so within the DO WORK section above, we add this:

$subscribe = get_comment_meta($cid, 'mailchimp_subscribe', true);
if ( $subscribe == 'on' ) {
  // DO WORK
}

We're checking for "on" because that's how PHP stores a checked checkbox, and this way we can reuse the $subscribe variable later. Once we're sure the commenter wanted to be subscribed, let's get all the data we need to add a subscriber to our mailing list. To do that, we'll need to know:

• Our Mailchimp API key
• Our Mailchimp API endpoint server
• The Mailchimp list ID for the list you want to add the commenter to

Once you've got these three, we can create the post request:

$apikey   = ' <your API key> ';
$listid   = ' <List ID> ';
$endpoint   = 'http://<your endpoint>.api.mailchimp.com/1.3/?output=php';

$request   = array(
  'apikey' => $apikey,
  'id' => $listid,
  'email_address' => strtolower( $comment->comment_author_email ),
  'double_optin' => true,
  'merge_vars' => array(
    ' <merge tag for name> ' => $comment->comment_author,
    'OPTIN_IP' => $comment->comment_author_IP,
  )
);
$result = wp_remote_post(
  $endpoint.'&method=listSubscribe',
  array( 'body' => json_encode($request) )
);

Note: setting double_option to false would forego the sending of an opt-in email, thereby immediately subscribing people to the list. Do not do this as it is illegal in most parts of Europe and in the US to do so.

As you can see, we're using the WP_HTTP wrapper function wp_remote_post to handle the post. At this time I'm not actually doing anything with the result, because I'm a sloppy coder. You should of course check the result and based on that do the following action:

update_comment_meta($cid, 'mailchimp_subscribe', 'subscribed', 'on');

This will prevent the code from trying to subscribe someone multiple times and overloading the MailChimp API.

Conclusion: Subscribe those commenters!

People are interacting with your site already, they're already giving you their email address, have them check that box, and make them subscribe to your list. I personally think it's a great enhancement that would make a lot of people happy. If you're not using Mailchimp but another email provider and are capable to do the same stuff with their API: please post about it, drop a comment here and I'll add a link!

Disclosure: Mailchimp sponsors my newsletter and is a regular advertiser on my sites.

Turn your commenters into subscribers! is a post by Joost de Valk on Yoast - Tweaking Websites.A good WordPress blog needs good hosting, you don't want your blog to be slow, or, even worse, down, do you? Check out my thoughts on WordPress hosting!

I value comments a lot, in fact, I look at the number and quality of comments on a post almost as much as I look at the number of shares, tweets and pageviews to determine how well a post was received. Recently I've done some posts that got a lot of annoying responses. Most of those were anonymous comments, which lead me to change my comment policies a bit to prevent those from happening in the future.

This tactic might work for more people, so I thought I'd share it:

Confirming the comment e-mail address

Using a plugin called comment e-mail verification I now force people to use a real e-mail address when commenting. The process is simple: if you comment for the first time, your comment will be kept in moderation automatically. You'll get a confirmation e-mail with a link in it. Clicking that link will take your comment out of moderation and place it immediately.

The plugin allows you to change the email message sent to the end user as well as some other things, but mostly just works. I use this plugin in conjunction with my own comment redirect plugin, which takes people who comment here for the first time to a special thank you page. This page looks like this:

So the process goes like this, when someone comments here for the first time:

• Visitor leaves a comment.
• Visitor is redirected to the comment thank you page, which states, among other things, that they have to confirm their email address.
• Visitor clicks the confirmation link in his / her email, which takes the comment out of moderation.
• The visitor is redirected immediately to the comment.

Funnily enough, I now see visitors leave the same comment twice. Once with a fake e-mail address, and then later on with a real e-mail address.

Next to the measures above, I've also added some statements to my Comment Rules, above the comment submit button. I now strictly adhere to these rules:

• Keywords instead of a real name? Comment gets deleted.
• A fake name instead of your real name? Comment gets deleted.
• A comment "signature" (with or without links)? Signature gets deleted first time, second time, comment gets deleted.

I'm curious though, most of you reading this are bloggers, what do you do to prevent not just comment spam but annoying comments and commenters?

Top image from Shutterstock.

Preventing anonymous comments in WordPress is a post by Joost de Valk on Yoast - Tweaking Websites.A good WordPress blog needs good hosting, you don't want your blog to be slow, or, even worse, down, do you? Check out my thoughts on WordPress hosting!

I wanted to talk a bit more about Gravity Forms though. I have my own contact form plugin, and yet, I have decided to go with Gravity Forms for all the contact forms on this site, and it's now the only contact form we use for all our client projects.

It is that, for several reasons. Most important: it's bloody easy to use. No programming needed anymore if the client wants another line of input added, needs a captcha or a file upload, wants a drop down or even wants people to be able to submit content directly to the site through a form.

Second: it stores all contact entries in the database, and has an easy to use interface to search through and export them into something like, for instance, a csv file. This way, if the notification email goes wrong, there's still a copy on the server.

There's loads more, as I said, both my contact form and my hire me form are now built with Gravity Forms, so I can only say: go get it. Carl was so kind as to leave a promo code especially for Press This listeners, which I don't think he'll mind if I share here: use PRESSTHIS as a coupon code for an instant 20% discount!

Gravity Forms on Press This is a post by Joost de Valk on Yoast - Tweaking Websites.A good WordPress blog needs good hosting, you don't want your blog to be slow, or, even worse, down, do you? Check out my thoughts on WordPress hosting!

There's a couple of ways to go about this, but what I decided to do was the following:

function mail_feed_query($query) {
	if ($query->is_home || $query->is_front_page) {
		$query->set('cat','-120');
	}
	return $query;
}
add_filter('pre_get_posts','mail_feed_query');

(120 is the category ID here)

This filters out the query from the home page and/or front page of your blog. Now you'll need to do a bit of extra work to prevent it from showing up in category listings, everywhere you do a get_categories or wp_list_categories you just add &exclude=120 (where, again, 120 is the category ID).

So as of next week, my WordPress newsletter will be having its own unique articles again, as well as all the articles in the WordPress category. So, subscribe, like, now, so you don't miss any of the goodness!

One of the things I intend to send out only to my newsletter subscribers is the new plugins I come across that I like or find useful, so if you don't subscribe to the newsletter, you're really missing out.

Excluding a blog category from your feed is a post by Joost de Valk on Yoast - Tweaking Websites.A good WordPress blog needs good hosting, you don't want your blog to be slow, or, even worse, down, do you? Check out my thoughts on WordPress hosting!

Hey Sherman, can you give us a short introduction of yourself and your work experience?

I first started working in the software industry at really terrific company called Broderbund, where I worked in the product management group on titles such as "Prince of Persia 2" and "Where in the USA is Carmen Sandiego." After Broderbund, I was a program manager at Apple for several Mac OS technology components, including AppleScript and OpenDoc. I then spent seven years at Sun Microsystems in the Java Software group, where I was the product management lead on J2SE 1.4.

A desire to get back to user-facing software led me to Mozilla, where I met my co-founder, Scott MacGregor. We realized that we shared a similar vision for email and productivity, and from that, Postbox was born.

Can you tell us what Postbox is?

Postbox is a new desktop email application that dramatically improves the way people find, use, and organize email messages and content. We’re currently in public beta for our 1.0 version, and anyone can download the beta from our website.

What made you dive into creating Postbox?

Advanced Search

We didn’t feel our software tools were doing enough to help people stay productive. We’re literally drowning in information, and it’s becoming increasingly difficult to make sense of it all. For example, we found that many people simply keep everything in the inbox, essentially living out of their inboxes because it’s too much effort to keep everything organized within folders.

And while message volume is certainly a contributor to overload, we also found that messages were being used for functions they were never designed to support. We leave messages in our inboxes because they remind us of things we need to do, or because they contain a document or a piece of information. How many times have you emailed a message to yourself, and did that feel like an elegant way to work with email?

We’re building Postbox so that people can spend less time managing email, and more time using email to get stuff done.

What are the main reasons for people to switch to Postbox?

We can save people a lot of time by providing very fast ways to find and use messages and content. In Postbox, you can get instant access to all of your files, images, and links in just one click, and then perform useful actions on the content that you’ve found. For example, if a relative asks for more recent family photos, simply hit reply and search through all images stored within your email – directly within your message reply window.

Message Compose with Attachment Search

We also make it easy for people to organize messages by topic, which essentially creates a lightweight activity space to work within. People can quickly assign a topic to a group of messages, and then jump into that topic to get stuff done. This allows people to stay focused on just one thing at a time, while minimizing interruptions from unrelated messages. Topics can also be combined with Postbox search to get faster access to the content that is most relevant to your current activity.

Finally, because we’re a desktop application and do everything locally, you can use Postbox with either your work or home accounts, while maintaining the privacy and confidentiality of your email information.

What's your business model?

We're currently evaluating a variety of options, but no decisions have been made to date.

What are some of the features you will be adding in the near future? Are you guys going to offer email hosting like RackSpace perhaps?

We have some great features in the pipeline, but in the near term, our Beta 10 release will contain a new way to add custom signatures to your messages. You can create a variety of rich HTML signatures, and then quickly select which signature you would like to use directly within a new message window. It's pretty slick, and it actually turned out to be kind of fun to use.

We'll also be adding in support for additional content types to search for, and we'll be providing new ways to view, organize, use and share this information within email and online.

Any closing thoughts?

Postbox works great with any POP or IMAP account, so I would encourage everyone to try it. We're still in beta, so there's a lot of active development going on. Since we release a new version about every three weeks, there's always something new to check out.

Thanks Sherman for your time, and everyone, go try Postbox!

Postbox, an interview with Sherman Dickman is a post by Joost de Valk on Yoast - Tweaking Websites.A good WordPress blog needs good hosting, you don't want your blog to be slow, or, even worse, down, do you? Check out my thoughts on WordPress hosting!

• I use a lot of links, and these were breaking up even a simple text layout, and I figured HTML email would increase the readability of the whole thing.
• With HTML emails, because you're seeing normal link text, it doesn't look so bad when you're tracking clicks, which you are of course doing to improve your newsletter.
• HTML email plain looks better, and gives a better opportunity to brand yourself.

In the process of switching to HTML, I've learned a couple of things. I must say the first thing I've learned is that people don't really seem to mind getting HTML email, I've had 1 serious complaint and about 5 dozen positive reactions of people saying this hugely improved the newsletter.

The funny thing is that the 1 serious complaint taught me something new: my newsletter wasn't showing up very nicely in Yahoo! Mail, and the guy was right on to complain to me. Turns out, a lot of web based email readers don't like external style sheets. The solution is simple: use only inline styles.

Now that might seem like a lot of work, but it isn't because of this great tool called Premailer. That absolutely great tool allows you to make up your newsletter in HTML, and then it parses it and moves it all to inline styles. In the same process, it'll also created a decently looking text version!

So I based my design on one of these templates provided by Campaign Monitor, and got my buddy Christian to design this header image for me:

So what I've done now that I've got a finished template is perhaps a bit geeky, but I love it: I've set up a special WordPress blog, with the email template as it's template. I've reversed the post order in it, which you can do by simply doing this:

// Reverse post order
query_posts($query_string . "&order=ASC");
while (have_posts()) : the_post();

And now I can use my favorite external editor, MarsEdit, to write posts for my mailing list. I tag each post with it's edition number, and when I've got enough stuff for a new edition, I open up that tags page, save the HTML, put it through Premailer and then copy the parsed HTML from Premailer into my Aweber broadcast. As Premailer also provides the plain text version, I copy that in too, and I'm done!

By the way people have asked me why I use Aweber, and to be honest I haven't tried anything else. This is what most pro's I know use, it's pretty cheap, it's very good, and it gives me everything I need, so why go look somewhere else?

All in all, this has been a pretty smooth experience, and my newsletter has gotten better from it, so I would advice any of you who sent out text only emails to start doing HTML too!

Switching from plain text to HTML emails is a post by Joost de Valk on Yoast - Tweaking Websites.A good WordPress blog needs good hosting, you don't want your blog to be slow, or, even worse, down, do you? Check out my thoughts on WordPress hosting!

Sociable 2.6.7

• Renamed Sk*rt to Kirtsy
• Added designfloat
• Fixed the descriptions

Slideshare 1.1
I recoded the SlideShare plugin to make it use the Shortcode API, which made the code 25% smaller.

Permalink Redirect 1.0
This plugin had an issue where it made it impossible to look at preview pages, which I've fixed. I've also uploaded the plugin to WordPress.org.

Blog Metrics 1.1
Fixed a few divisions by zero when authors had 0 posts, or when there weren't any trackbacks.

Comment Redirect 0.1
No fixes, but I did upload this plugin to WordPress.org for the first time, so auto update should start working for this plugin as well.

Robots Meta 3.0.3
Thanks to Henryk Gerlach, a noarchive option was added to Robots Meta.

New: Email Commenters 0.1
Sometimes you want to email all people who commented on a certain post. This plugin gives logged in admins an easy way to do that by adding a mailto: link to do just that underneath each post.
Update: this plugin has already been added to the WordPress plugin repository as well!

Several plugin updates and a new plugin! is a post by Joost de Valk on Yoast - Tweaking Websites.A good WordPress blog needs good hosting, you don't want your blog to be slow, or, even worse, down, do you? Check out my thoughts on WordPress hosting!

Another nice thing a friend pointed me at today is that if you're sending out email, at all, and you host or register your domains through GoDaddy, you might be in for some pain. Apparently, they can take your domain hostage if someone files a spam complaint... GoDaddy never had the best reputation, but this is another reason to urge you to switch away from them.

Annoyances and weird stuff is a post by Joost de Valk on Yoast - Tweaking Websites.A good WordPress blog needs good hosting, you don't want your blog to be slow, or, even worse, down, do you? Check out my thoughts on WordPress hosting!