Posted: July 8, 2020 at 4:49 pm
I am using our EE4 Everything license, and setup is complete; we’re in test mode at this time hoping to go live with some events for the fall. We were hoping to go live today, but ran into this unexpected issue.
When we tested the registration for one of the events we have setup, the confirmation message states an e-mail has been sent. Notwithstanding this, the e-mail never arrived. We have performed this test a couple of times, and still no e-mails arrive.
To manage the site’s SMTP functions, we’re using the WP Mail SMTP plugin which is integrated with Amazon SES. All our regular messages / site notifications from other plugins are going out okay. The website is part of a WP multi-site installation, hosted on one of our Amazon EC2 instances. The mail client connects to an Office 365 exchange server to retrieve e-mail messages.
From a Google search I found this 2016 forum post:
which suggests we need to create a modification to the functions.php file to accommodate.
I see that I am not the only one with this issue recently, as this post reflects a similar issue:
I’m assuming where WP Mail SMTP logs reflects the e-mails leaving the server, this is another case of SES rejecting the messages due to the double header issue, per the referenced forum post. Would that be a safe assumption?
If so, is the proposed code insertions into the functions.php file still the best solution / resolution?
If not, any suggestions?
As one additional point of clarification / background information, e-mail has been flowing into the e-mail client all day without issue from other sources, as well as other site notifications being dispatched by WP Mail SMTP plugin / Amazon SES.
In light of this, we ruled out an issue between Amazon SES and Office 365 Exchange server.
So the email shows as sent in EE and has a green status bar (the coloured bar to the left)?
If so, then EE generated the email and passed it over to wp_mail() which did not return any errors. So as far as EE has control over, EE ‘sent’ the email as expected and no errors were thrown.
Unfortunately, you’ll find many different threads for email issues as there are lots of different email configs. Many users use their hosts own mail server to send the emails which is where the majority of issues come from.
Safe, yes, but without the error being thrown (which apparently isn’t all that simple to pull from SES) you can’t be sure.
It depends on what was setting the additional MIME-Version
The quickest way to test if this is the problem on your site is to add the code referenced above and run another test, if it works it was the MIME-Version header (as that is the only header that code removes). It’s not going to affect any other emails sent by your site as the hook in question runs only within Event Espresso.