[FFmpeg-user] Missing emails as cause of domain relocation

[Reindl Harald]

Am 04.09.23 um 15:16 schrieb Ulf Zibis:
> 
> Am 04.09.23 um 14:59 schrieb Reindl Harald:
>>>> Am 04.09.23 um 14:35 schrieb Ulf Zibis:
>>>>> because of a domain relocation, my email was not reachable from 
>>>>> 2023-09-01 13:54 UTC to 2023-09-04 11:38 UTC.
>>
>> because it takes time?
>>
>> the interval of retries increases as it makes no sense trying every 5 
>> minuts
> 
> OK, so I can hope until 2023-09-04 13:54 UTC for a last retry ?

it depends on the sending server how long it will retry

>> for one moron which don't manage a server relocation
> The moron, who made a typo on the dns records, was the webhosting 
> provider, and on weekend he was not reachable.

well, don't do changes you can't do alone in front of a weekend

>> seriously - the expected downtime is seconds to minutes when properly 
>> planned even for thousands of accounts
>>
>> * new system online
>> * DNS TTL down to 5 minutes
>> * imapsync
> this took 16 hours, so little more than 5 minutes

irrelevant - this is the first sync so that finally only the diff of the 
new messages needs to be transmitted

years ago i migrated a few hundret domains with around 150.000 messages 
with exactly 20 seconds downtime

>> * take down the MTA on both sides
> What is MTA?

oh my god - and you are operating a mailserver? - that little to no 
knowledge about mail explains the naive question about resend list mails

https://en.wikipedia.org/wiki/Message_transfer_agent

the idea is to make sure no new mails arrive on both sides while the 
final message sync is running and finally turn only the new one up

so delivering MTA's with outdated DNS infos fail on the old one and the 
next retry happens on the new server

while the sync is running no messages are accepted at all which is no 
problem given that any serious mail system retries anyways

>> * change dns record
>> * final imapsync
>> * start MTA
>> * done
> 
> And thanks for the recipe ... for the next time