Mandatory (OK, not mandatory—recommended) Mandrill

[alan]

I was put on to Mandrill by Pete (thank you Pete).

In my experience if your website sends emails to people, for example you have a booking app and people get confirmations, then the confirmation emails may, sometimes, get rejected as spam, regardless of the fact that they're not.

TL;DR

Whenever in the PW admin there is a field to do with delivery of email from PW, there ought to be a note / link to an article about the benefits of sending email via Mandrill (or similar service) rather than direct.

Boring rant version

I had tried to solve this lack of 100% reliable email delivery with

• DKIM and SPF records (good things in their own right)
• tuning the content of the email so perhaps it would be less likely to apparently trigger some spam pattern recognition code (for example having few(er) HTML links
• banging my head
• shouting

Nothing worked. I would appear to have a period of reliability where all emails were getting through, relax... Then BAM! Another spam rejection.

The only variance? The receiving email systems. As visitors to the site were many and varied so were their email systems and some of those email systems spam detection algorithms were simply too sensitive for their own good.

So it was not my fault but nevertheless my client whose website used the booking system kept gettings infrequent but repeated 'lost' email confirmations.

So I made one other change, I sent email via SMTP to Mandrill rather than directly to the client. Mandrill then sent it to the client.

This resulted in an unprecedented (and continuing) period of 100% success—zero false positive spam rejections.

The reason is simple: my client's domain (or your client's domain) has a reputation as a source of email. It is probably average or good. Whereas Mandrill, who send

10 billion emails every month for more than 7 million customers [source]

(Mandrill is part of MailChimp and these are the overall numbers) with this many emails have to have an exceptional reputation, and they do.

Nothing I can do on a domain or in DNS can compete with this firehose of good reputation provided by Mandrill.

Recommendation

If I were a newbie to emailing from PW to people then I could well go through this learning curve myself. To help others I would like to suggest that perhaps wherever there is a field in PW that is responsible for sending email that one of those helpful 'Notes' be auto populated with a link to an article on on the benefits of sending email via an intermediary such as Mandrill.

[muzzer]

Thx for this Alan, been checking out Mandrill since reading your post earlier, and running some test emails etc. Looks like a pretty sweet system. Will check out the API over the weekend as that looks pretty sharp also I think I'll be moving all my site emails to Mandrill. Cheers. 

[alan]

Welcome muzzer. So far I've used Horst's module for SMTP connection but this module looks interesting and is clearly aimed at API connection rather than SMTP—looking forward to trying it out.

[clsource]

I have used Mandrill in a PW project before

using the PHP Client.

https://mandrillapp.com/api/docs/index.php.html

Straight foward and easy to implement.

I didn't use the stmp because I was using Mandrill templates

and filling the placeholders with user data.