Hi,
Here's an extract from a site about 421:
SMTP Error 421
421 Temporary System Problem. Try again later.
421 Try again later, closing connection.
421 Server busy, try again later.
The SMTP error 421 is normally used for temporary problems on the mail
server or a problem with the recipients email account.
Some mail providers might also return 421 after you reached a limit
(restriction) on your mail account (see SMTP Error 451 below).
Does this help?
Suggesting the RFC be modified is off the table, because that is not the
problem. RFC's are very seriously thought out and hugely important
documents, tested and approved by serious committees. Looking. Sure,
they get updated, but not for reasons related to issues like this.
Andrew
On 29/8/19 12:36 pm, Eliza wrote:
I know postfix returns 4xx Response Code for Temporarily Deferred, as
below:
----- The following addresses had fatal errors -----
[Status: Error, Address: <e...@chinabuckets.com>, ResponseCode 421,
4.7.0 Temporarily Deferred]
Message will be retried for 4 more day(s)
I don't like every MTA returns this 4xx code, that would make the
incoming messages delay a lot time.
How do you think of this? should RFC reconsider to disable 4xx code?
