Hi Claudio, About Libero (IOL) try to use a single connection. I got that error by using 2 concurrent connections from the same IP: you can send very fast but you can only use a single connection. I've never been able to get in touch with a Libero postmaster recently.
About Yahoo from what I saw they have an hourly rate limiting that is being reset at the 30 minute of each hour and a daily limit that resets at 3 in the night (CET): the 2 limits depend on your IP reputation, so you can try delaying 1 hour for the first retries and 1 day for the next ones, until yahoo learn your IP reputation. Yahoo postmaster is here in the list. Stefano On Thu, 4 Apr 2024 at 01:07, Claudio Faoro via mailop <mailop@mailop.org> wrote: > > Hi everyone, > > a couple of weeks ago I configured a new Postfix server, it's used > exclusively by a newsletter service with 20000 subscribers. > The newsletter service has been active for more than 10 years on a very old > server running qmail. > Unfortunately, I had to decommission the old qmail server in a few days, > replacing it with the new one. It was not possible to keep the same IP > address. > I've correctly configured the SPF, DKIM, DMARC and PTR records > (mail-tester.com gives me 10/10). > The first few days, I had problems delivering mail to several providers due > to the amount of messages. I guess it's partly due to the new IP. > For example: > > Mar 30 15:37:00 mx1 postfix/smtp[2021]: 6940F7FF09: to=<REDACTED>, > relay=mx-eu.mail.am0.yahoodns.net[188.125.72.74]:25, delay=3473, > delays=0.47/3472/0.71/0.04, dsn=4.7.0, status=deferred (host > mx-eu.mail.am0.yahoodns.net[188.125.72.74] said: 421 4.7.0 [TSS04] Messages > from REDACTED temporarily deferred due to unexpected volume or user > complaints - 4.16.55.1; see https://postmaster.yahooinc.com/error-codes (in > reply to MAIL FROM command)) > > After a few mailings, the situation seems to have stabilized, Yahoo no longer > gave me problems. > Unfortunately, a good percentage of our subscribers use an email address from > Italiaonline/IOL (libero.it, virgilio.it, iol.it, inwind.it, etc...). > Most of the emails to IOL get bounced: > > Mar 30 00:15:40 mx1 postfix/smtp[51700]: 509762617D: to=<REDACTED>, > relay=smtp-in.libero.it[213.209.1.129]:25, delay=116950, > delays=116848/101/0.09/1.1, dsn=4.0.0, status=deferred (host > smtp-in.libero.it[213.209.1.129] said: 451 too many messages, slow down. > [smtp-22.iol.local; LIB_650] (in reply to end of DATA command)) > > The limit is triggered very quickly and it's removed after several hours. > I tried to throttle the sending to IOL addresses on Postfix > (destination_concurrency_limit = 2 and destination_rate_delay = 300s), but I > keep getting capped after a while. > I don't have much information regarding the old qmail server, but it seems > that there were not all these problems (there wasn't even DKIM and DMARC > configured!). > > I don't understand how to resolve these problems with the libero.it mailboxes > (and more generally, with all Italiaonline mailboxes). Do you have a contact > in Italiaonline who can help me? > Any info would help me, thanks in advance. > > Regards, > Claudio -- Stefano Bagnara Apache James/jDKIM/jSPF VOXmail/Mosaico.io/VoidLabs _______________________________________________ mailop mailing list mailop@mailop.org https://list.mailop.org/listinfo/mailop
