Issue Emails do not leave the email queue

[PREFA]

Hello and good day!
I have a problem with sending e-mails that I cannot solve on my own:
After a server migration: The outgoing mails do not leave the email queue. First there is a green tick, then a red arrow (means postponed) The mails will not be sent later either.
MX lookup looks good.
But all mails are received without errors.
Maybe someone had the problem before?
Thanks in advance!

 

[Bitpalast]

Have you looked into the mail log to see what is actually happening to single mails that stay in the queue?

 

[PREFA]

Have you looked into the mail log to see what is actually happening to single mails that stay in the queue?

Hello again, here is an excerpt from the mail log:



Sep 28 11:58:33 host postfix/smtpd[52308]: warning: dict_nis_init: NIS domain name not set - NIS lookups disabled

Sep 28 11:58:33 host postfix/smtpd[52308]: connect from 213162073012.public.t-mobile.at[213.162.73.12]

Sep 28 11:58:33 host postfix/smtpd[52308]: TLS SNI mail.example.at from 213162073012.public.t-mobile.at[213.162.73.12] not matched, using default chain

Sep 28 11:58:33 host postfix/smtpd[52308]: DC99415145D: client=213162073012.public.t-mobile.at[213.162.73.12], sasl_method=CRAM-MD5, sasl_username=exampl@example.at

Sep 28 11:58:34 host postfix/cleanup[52314]: DC99415145D: message-id=<df241097-d511-91c6-aa71-94d7a1df613e@example.at>

Sep 28 11:58:34 host check-quota[52317]: Starting the check-quota filter...

Sep 28 11:58:34 host psa-pc-remote[23246]: SKIP during call 'check-quota' handler

Sep 28 11:58:34 host spf[52319]: Starting the spf filter...

Sep 28 11:58:34 host spf[52319]: SPF status: PASS

Sep 28 11:58:34 host psa-pc-remote[23246]: PASS during call 'spf' handler

Sep 28 11:58:34 host dk_sign[52320]: Starting the dk_sign filter...

Sep 28 11:58:34 host psa-pc-remote[23246]: PASS during call 'dd51-domainkeys' handler

Sep 28 11:58:34 host postfix/qmgr[23294]: DC99415145D: from=<example@example.at>, size=635, nrcpt=1 (queue active)

Sep 28 11:58:34 host postfix/smtpd[52308]: disconnect from 213162073012.public.t-mobile.at[213.162.73.12] ehlo=1 auth=1 mail=1 rcpt=1 data=1 quit=1 commands=6

Sep 28 11:58:34 host courier-imaps[23012]: Connection, ip=[::ffff:213.162.73.12]

Sep 28 11:58:34 host courier-imaps[23012]: LOGIN, user=example@example.at, ip=[::ffff:213.162.73.12], port=[28007], protocol=IMAP

Sep 28 11:58:35 host courier-imaps[23012]: LOGOUT, user=example@example.at, ip=[::ffff:213.162.73.12], headers=0, body=0, rcvd=447, sent=129, time=1, starttls=1

Sep 28 11:59:04 host postfix/smtp[52321]: connect to gmail-smtp-in.l.google.com[64.233.167.26]:25: Connection timed out

Sep 28 11:59:04 host postfix/smtp[52321]: connect to gmail-smtp-in.l.google.com[2a00:1450:400c:c0a::1a]:25: No route to host

Sep 28 11:59:34 host postfix/smtp[52321]: connect to alt1.gmail-smtp-in.l.google.com[209.85.233.27]:25: Connection timed out

Sep 28 11:59:34 host postfix/smtp[52321]: connect to alt1.gmail-smtp-in.l.google.com[2a00:1450:4010:c03::1b]:25: No route to host

Sep 28 11:59:38 host courier-imaps[23012]: Connection, ip=[::ffff:213.162.73.12]

Sep 28 11:59:39 host courier-imaps[23012]: LOGIN, user=example@example.at, ip=[::ffff:213.162.73.12], port=[28008], protocol=IMAP

Sep 28 12:00:04 host postfix/smtp[52321]: connect to alt2.gmail-smtp-in.l.google.com[142.250.4.26]:25: Connection timed out

Sep 28 12:00:04 host postfix/smtp[52321]: DC99415145D: to=<receiver@gmail.com>, relay=none, delay=90, delays=0.31/0.01/90/0, dsn=4.4.1, status=deferred (connect to alt2.gmail-smtp-in.l.google.com[142.250.4.26]:25: Connection timed out)

 

[Bitpalast]

Looks like Gmail is blocking your host. Have you check whether it is listed on blacklists for sending spam in the past?

MultiRBL.valli.org - Blacklist, Whitelist and FCrDNS check tool

Free multiple DNSBL/RBL lookup and FCrDNS check tool. Test the IP (IPv4 or IPv6) of your mailserver on more than 200 blacklists and whitelists.

multirbl.valli.org

 

[PREFA]

DNSBL Blacklist Test Summary54 of 54 tests done.ResultsNot listed: 54Blacklisted: 0Brownlisted: 0Yellowlisted: 0Whitelisted: 0Neutrallisted: 0Failed: 0ProcessingAll doneDNSBL Combinedlist Test Summary6 of 6 tests done.ResultsNot listed: 6Blacklisted: 0Brownlisted: 0Yellowlisted: 0Whitelisted: 0Neutrallisted: 0Failed: 0ProcessingAll doneDNSBL Whitelist Test Summary7 of 7 tests done.ResultsNot listed: 7Blacklisted: 0Brownlisted: 0Yellowlisted: 0Whitelisted: 0Neutrallisted: 0Failed: 0ProcessingAll doneDNSBL Informationallist Test Summary1 of 1 tests done.ResultsNot listed: 1Blacklisted: 0Brownlisted: 0Yellowlisted: 0Whitelisted: 0Neutrallisted: 0Failed: 0ProcessingAll done

Not blacklisted...
It affects every email address, except the one hosted on my own server. These are delivered as normal

 

[Bitpalast]

Are the IPs 64.233.167.26 and 2a00:1450:400c:c0a::1a blocked by Fail2Ban on your own server?
If a connection to these Google server is not possible, it is for sure an issue with an ip block.

 

[PREFA]

I deactivated Fail2ban, restarted the server, without success. A pity

 

[Bitpalast]

Have you tried to find out more about what Google thinks of your addresses?

Check MX: Check MX and SPF Records.

toolbox.googleapps.com

You can also try some of these hints:

Rejected messages - Gmail Help

 

[PREFA]

Many thanks for the help.

The solution is this:

By default, IONOS blocks port 25 for outgoing connections on all new servers. You have to contact the support, then they will check and open the port for you. After setting up the server, at least I didn't see any evidence of it.

My emails are arriving, yeah

Have a nice day everyone!