While a great point, this is not actually an issue in production.
If the SMTP server is somehow unreachable, the server is crashing as the SMTP the app talks to is local on the server (postfix to be exact). This local server puts it in a queue to sent it to the UU SMTP. If the UU SMTP is offline, the local queue is kept till it comes back.
tymees
commented
2 years ago
While a great point, this is not actually an issue in production. If the SMTP server is somehow unreachable, the server is crashing as the SMTP the app talks to is local on the server (postfix to be exact). This local server puts it in a queue to sent it to the UU SMTP. If the UU SMTP is offline, the local queue is kept till it comes back.