On Tue, Oct 11, 2022, 1:00 PM Wietse Venema, <wie...@porcupine.org> wrote:
> <snip > > > How long do servers try to resend email if your server is temporarily > down? > > The host has given themselves an 8 hour overnight window. > > "It depends". There is a difference between wat rules say (in this > case https://www.rfc-editor.org/rfc/rfc5321#section-4.5.4) and what > real systems do. But the rules are still a good guide. > > Postfix retries for 5 days with intervals that slowly increase from > 5 minutes to 4 hours. But with a queue of millions of files it may > take an unreasonable amount of time to catch up. > > Other systems may give up after hours, to prevent the mail queue > from becoming unreasonably large. > Thanks. Thankfully, this is a small email server (me & the missus) and six addresses. 99.9999% of the legitimate biz contacts that email us do so between 9am and 8pm EST so at worst we'll miss some spam. I'd say on a busy day the server receives <90 legitimate emails. >
