> 20. okt. 2020 kl. 12:41 skrev Daniele Rossi via mailop <mailop@mailop.org>: > > Hi, > > we try to send to Microsoft Account and we receive this message: > > Queued mail for delivery -> 250 2.1.5 > The problem is that the mail does not arrive either in spam or in the inbox. > This happens for most of our ip's. > >
That should simply not happen, ever. You could report a temporary problem (as in greylist), otherwise the valid options are to reject (bounce) or accept and deliver, optionally with spam tagging if checks on headers or content warrant that. > Can anyone explain this abnormal behavior to me? > Your report is not the first that indicates that the company in question has built itself a mail transfer and delivery architecture that is getting far more complex than needed (my own https://bsdly.blogspot.com/2018/02/a-life-lesson-in-mishandling-smtp.html <https://bsdly.blogspot.com/2018/02/a-life-lesson-in-mishandling-smtp.html> is another example), and they’re not very good at actually communicating with people reporting problems. There is always a chance that there *could* be some seemingly minor issue at your end, however, so please check that * any host involved in delivering mail for your domain(s) has a valid reverse record for all IP addresses (IPv4 and IPv6 both), and that * your name service delivers valid results for such things as SPF, DMARC The second actually bit me recently — a common BIND misconfiguration will try to send too-big-to-fit-in-one-packet answers via UDP with predictable results for SPF queries, leading to quasi-random failures claiming SPF failures due to timeout now that people actually started using the info in earnest after only about 20 years of ignoring. Essentially your named.conf needs somewhere in its options block edns-udp-size 1232; max-udp-size 1232; Other implementations will have similar tweakables. All the best, — Peter N. M. Hansteen, member of the first RFC 1149 implementation team http://bsdly.blogspot.com/ http://www.bsdly.net/ http://www.nuug.no/ "Remember to set the evil bit on all malicious network traffic" delilah spamd[29949]: 85.152.224.147: disconnected after 42673 seconds.
signature.asc
Description: Message signed with OpenPGP
_______________________________________________ mailop mailing list mailop@mailop.org https://list.mailop.org/listinfo/mailop
