Interesting! Emails that stop sending can be caused by a technical glitch of some kind, or they can be the consequence of a block list. A sister project could be to assist users with this?
A couple of years ago I built a journal system that sends me an email everyday; answers are then logged in a db. It worked flawlessly until last week.
Although that domain is only used by me to send emails to me, it seems it was suddenly added to a black list (DNSBL). I would welcome assistance in that matter and am not sure where to turn to... (Mailgun support essentially says "tough luck").
A simple follow-up if someone finds this later: it turns out support for the two relevant black lists are super responsive and nice. The domain had been blacklisted in error; it was delisted immediately. It was surprising how fast and nice that went ;-)
A couple of years ago I built a journal system that sends me an email everyday; answers are then logged in a db. It worked flawlessly until last week.
Although that domain is only used by me to send emails to me, it seems it was suddenly added to a black list (DNSBL). I would welcome assistance in that matter and am not sure where to turn to... (Mailgun support essentially says "tough luck").