Amazon supposedly distinguishes between soft and hard bounces, and only hard bounces count towards your failure rate for which you eventually might be penalised

Amazon supposedly distinguishes between soft and hard bounces, and only hard bounces count towards your failure rate for which you eventually might be penalised: https://github.com/awsdocs/amazon-ses-developer-guide/blob/ec08804/doc-source/sending-concepts-deliverability.md https://github.com/awsdocs/amazon-ses-developer-guide/blob/e... Although annoyingly in the case of a soft bounce they apparently only retry for up 12 hours, which for a small mail server is very much on the too short side: In the worst case my mail server/hoster goes down just as I go to sleep, in the morning I either don't notice it or can't do anything about it anyway as I need to go to work, at work I can't do anything about it either, and it's only when I get back home that I can stand up my emergency mail server if the outage hasn't resolved itself by that time, which means > 20 h of down time and therefore far exceeding Amazon's retry window. (The RFC5321 recommendation is to keep retrying for 4 to 5 days, which is much more amenable for that case)