No emails are being sent, SMTP plugin test emails are getting through fine

Until a couple of months ago, everything was working fine, however, subscribe by emails seems to have stopped working.
I have installed WP-Mail-SMTP, and using php mail I can send test messages from this plugin successfully.
However, no emails are being sent from 'Subscribe by email'.
Confirmation emails aren't being sent, test emails aren't being sent, updates aren't being sent. The latest post was created a week ago. Nobody received it. There is nothing in the log, either sent or waiting to be sent.There are no errors being reported in any log files.
The site is, and I have granted support access
Kind Regards

  • Dimitris

    Hey there Johanna,

    hope you're doing good today! :slight_smile:

    I just tried to replicate this with WP SMTP plugin using the mail() function with no avail. In either situation both confirmation and test emails were sent.

    Having said so, can you please proceed with a theme/plugin conflict test? You can find a nice flow chart in
    This way we either find a conflict or be sure that this is a server side issue. :wink:

    I look forward for your results on this!
    Warm regards,

  • Johanna

    Have you tried it in a multisite environment with the plugin activated only for the one site?

    I have deactivated every plugin other that the WPMUDEV domain mapping, dashboard & subscribe by email, and i am still not receiving emails. Also, the site uses TwentyThirteen theme and everything is up to date.

    If it is a server-side issue (bearing in mind that wordpress and WP-SMTP-Mail are both able to send emails), how do I diagnose the problem

  • Adam Czajczyk

    Hello Johanna!

    I accessed your site and can confirm that test mails from WP SMTP plugin come through when it's set to use regular "mail()" function but no confirmation mails from Subscribe by Email are delivered from your setup.

    Therefore, I set Subscribe by Email on my multisite and activated it on a single sub-site only. I then installed WP Mail SMPT plugin and set it the same way as yours it on the same sub-site, including using gmail account. Both test mails and SbE e-mails are working on my setup still. I even used the same Twenty Thirteen theme.

    There's a difference though in set of other plugins installed, PHP version (I'm on 7) and of course server. I'm not stating any conclusive statement here that this is for sure a server issue but it's definitely strictly related to that particular setup.

    I'd like to ask you to test other option then. I checked whether WP Mail SMTP plugin may be causing this on your setup by temporarily disabling it but that is not the issue (plugin is up and running back again as it was). Could you then please configure the WP Mail SMTP fully to to send mails via Gmail SMTP?

    All information necessary to configure an application (WP Mail SMTP plugin in this case) to work with gmail are here:

    Let me please know if this changed a thing.

    Kind regards,

  • Johanna

    I've upgraded to Wordpress 4.6 and PHP 7.09. All plugins are up to date. When I now try to send a test email, I get the following:

    mod_fcgid: stderr: PHP Fatal error: Uncaught phpmailerException: Invalid address: no-reply@ in /var/www/vhosts/xxxx/wp-includes/class-phpmailer.php:946, referer: xxxx/wp-admin/admin.php?page=sbe-settings&tab=template
    mod_fcgid: stderr: Stack trace:, referer: xxxxxx/wp-admin/admin.php?page=sbe-settings&tab=template
    mod_fcgid: stderr: #0 /var/www/vhosts/xxxxxx/wp-includes/pluggable.php(352): PHPMailer->setFrom('no-reply@', 'from name...'), referer: xxxxxx/wp-admin/admin.php?page=sbe-settings&tab=template
    mod_fcgid: stderr: #1 /var/www/vhosts/xxxxxx/wp-content/plugins/subscribe-by-email/inc/mail-templates/classes/class-sbe-digest-sender.php(33): wp_mail('info@baobab-sol...', 'Vale Royal Ramb...', '\\r\\n<div style="f...', Array), referer: xxxxxx/wp-admin/admin.php?page=sbe-settings&tab=template
    mod_fcgid: stderr: #2 /var/www/vhosts/xxxxxx/wp-content/plugins/subscribe-by-email/admin/pages/admin-settings-page.php(1276): SBE_Digest_Sender->send_digest(Array, 'info@baobab-sol...'), referer: xxxxxx/wp-admin/admin.php?page=sbe-settings&tab=template
    mod_fcgid: stderr: #3 /var/www/xxxxxx/wp-includes/plugin.php(235): Incsub_Subscribe_By_Email_Admin_Settings_Page->sanitize_settings(Array), referer: xxxxxx/wp-admin/admin.php?page=sbe-settings&tab=template
    mod_fcgid: stderr: #4 /var/www/vhosts/xxxxxx/wp-includes/formatting.php(4270): apply_filters('sanitize_option...', Array, 'incsub_sbe_sett...', Array), referer: xxxxxx/wp-admin/admin.php?page=sbe-settings&tab=template
    mod_fcgid: stderr: #5 /var/ww in /var/www/vhosts/xxxxxx/wp-includes/class-phpmailer.php on line 946, referer:xxxxxx/wp-admin/admin.php?page=sbe-settings&tab=template

    Let me know if you want the exact error log entries - It's just the URL info that I have masked. The rest is as per the log

    This is with or without the SMTP plugin enabled. I can confirm that Wordpress emails are still getting through without a problem
    I've not tried the Google SMTP settings, as it doesn't even get that far!
    Kind Regards

  • Adam Czajczyk

    Hello Johanna!

    Thank you for your replay.

    This is with or without the SMTP plugin enabled. I can confirm that Wordpress emails are still getting through without a problem
    I've not tried the Google SMTP settings, as it doesn't even get that far!

    Enabling SMTP plugin doesn't change much unless the SMTP is fully configured: otherwise all e-mails are being directed through the same server and although SMTP plugin is "trying" to automatically set SMTP transport it rarely works on any server that way.

    When SMTP is fully configured the way e-mails are being send is changed. I understand that these errors came up even with the SMTP plugin enabled but from what you say I also understand that you didn't try to put full SMTP configuration for your Google mail there because of that. Could you please give it a try anyway? Even if the error comes up again it should give me a "full view" of what should I investigate further.

    Best regards,

  • Johanna

    Hi Adam,

    The errors included in the previous post was without the SMTP plugin enabled.
    We NEVER used to have an SMTP plugin for this - just used the standard wordpress functionality, until recently. And it all worked.
    I'll have a look at these Google SMTP settings tomorrow. I've had a long day, but surely a plugin shouldn't fail with a fatal error just because there is no SMTP plugin enabled?

  • Adam Czajczyk

    Hello Johanna!

    Thank you for all your responses and re-granting access. I checked the site again and run some more tests on it. I found another issue related to this: it seems that it may not be the case of e-mails not being delivered but rather not even being added to a queue.

    However, in order to check this and check for possible reasons (I already asked plugin's developer for initial help) I would need to access your setup in a more direct way. Please send in:

    Subject: "Attn: Adam Czajczyk"

    - Mark to my attention, the subject line should contain only: ATTN: Adam Czajczyk - Do not include anything else in the subject line, doing so may delay our response due to how email filtering works.
    - Link back to this thread
    - login URL and admin account login credentials (may be a temporary admin account) data
    - Include FTP log-in details (hostname, username & password)
    - Include hosting control panel access details (login address, username & password) -- cPanel's usually the control panel used for this, but your provider may use something else; I'll need this for accessing your site's database, preferably via phpMyAdmin
    - Include any relevant URLs for your site

    Please use our contact form here

    Select "I have a different question" from the drop-down list. 

    Please be sure to make a full backup of your entire site first!

    Best regards,

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