I have a suggestion for a new extension. Mail Uptime Monitoring. This would be very different from SMTP uptime monitoring.
You would need to provide a custom email on your Dashboard site’s server and give MainWP that account to monitor. This email account would be shared to the child sites who would send a regular email once (twice, thrice, etc.) daily (weekly, monthly). They would include some markers in the email/subject to show what child site/date/etc. The Dashboard site would track the incoming emails and validate them against what is expected and in this method it would ensure that each child site’s outgoing email is still working. It would delete each email once validated.
This would work for servers with their own email or those using WP SMTP to send outgoing emails via other servers.
If some email fails to validate, then trigger appropriate errors in the dashboard or email the admin.
Interesting @kwoodall I don’t think I’ve seen this suggestion before.
If I’m understanding you, the child site would send an email to an email address the Dashboard can query and then the Dashboard records what child sites it’s successfully got the email from and reports failed for any missing. Is that correct?
FWIW: This is an idea I came up with as some of my clients are on hosting, such as DigitalOcean and others, that don’t have their own mail servers and they use WP SMTP to send their mail. A system like this would provide reassurance that their mails are going out.
This is just a general statement and just me thinking out loud- I agree that this would be a good feature for such sites that do not use the php mail() method.
However, I think there is probably a more elegant solution then simply “sending out a mail.” Although a pretty old article, what @sebastian-moran has mentioned would be a better alternative to building a full solution with more feedback in the event that the mail system is actually not working. “It didn’t send” isn’t much feedback.
this was directed at the comment from @phalancs, who said it was not wanted as it was not about WP. I believe the opposite, it is mainly about WP ability to communicate, to admins, people that fill in forms, etc.