I’m using a plugin called Subscribe to Comments Reloaded, which allows viewers to respond and then receive emails if others respond. It also allows subscribing to a post to get emails even if they don’t leave a comment themselves.
If the person subscribing has a gmail domain email address, the mails go through to them. If they have a .mac or even an unusual domain, the emails are never received. The emails are not in spam or junk folders (I have tested with my own .mac email address to confirm this.)
I have confirmed, using both the WP Test Email plugin and the WP Mail Logging plugin that the emails were sent, but they are never received (to .mac and other domains).
The developer of Subscribe to Comments Reloaded is telling me that since WordPress confirms the mails have been successfully sent, that they might be being blocked by my hosting provider (Digital Ocean).
So, is it possible DigitalOcean is blocking some domains to receive email but not others?
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