Minimal mail client which doesn't rely on postfix? #email #postfix

https://askubuntu.com/q/1552575/612

New #blog post: "Signing sieve vacation auto-reply messages with dkim using postfix for deliverability"

I start my holiday, during which I intend to do less computer-touching, but doing some holiday-related computer-touching with my mailserver.

https://neilzone.co.uk/2025/07/signing-sieve-vacation-auto-reply-messages-with-dkim-using-postfix-for-deliverability/

because running a mail server wasn’t fun enough: the Dovecot 2.3 → 2.4 update has tons of breaking config changes

(h/t to https://willem.com/blog/2025-06-04_breaking-changes/ for the exhaustive breakdown of the changes)

Frage an die Schwarmintelligenz: Kann ich #postfix sagen, das es _als Server_ einige Mailhosts von der Vorgabe ausnehmen soll, TLS zu sprechen? Ich scheine Mailserver zu haben die zwar behaupten TLS zu können, aber dann die Verbindung abbricht. Diesen würde ich gerne kein TLS anbieten... was ist dafür das flag?

Gibt es in meiner Timeline jemanden, der professionellen #postfix #support leistet? Hab da ein #ispconfig3 Problem, welches mit etwas Postfix Wissen vermutlich schnell gelöst werden kann.

I have a #SysAdmin question: is it okay to use a local, loopback-only SMTP server (#mailutils + #postfix) to allow a local web app to send mails directly? Without any login/passwd?

This works fine:
echo [boty] | mail -s [subject] [dest]

But I can’t make it work from my app (#ApacheAnswer), even though it does have an unauthenticated mode for SMTP. What am I missing?

How much of a hit would the trustability and sending reliability of my #mailserver take if I change the just the domain, but not the IP etc ?

Nie mehr Ärger mit Blacklistings bei Microsoft – dank Transport Maps in Postfix/mailcow und einem kostenfreien Relayhost

https://andersgood.de/kurz-notiert/schluss-mit-blacklisting-bei-microsoft

#NerdSpeak Some mail senders are exposing internal, non-resolving host names in the EHLO/HELO phase when sending mails, causing my mail server to (correctly) refuse them. However, in some cases I have to begrudgingly accept their broken config as the mails they send are actually legitimate and important. Looking at you, Drillisch Online. Fix your shit. Anyway, here's how I did it on my #postfix server: https://codeberg.org/jwildeboer/gists/src/branch/main/2025/20250615HELOAllowlistPostfix.md

1/3

Any #postfix users know how to configure smtp_tls_wrappermode = yes for sending via a single relay, but not use it for others? I have things set up to relay via my outbound SMTP server to a few mail servers that all want STARTTLS over port 587, but now I want to add one that wants SMTPS over port 465. If I don't set smtp_tls_wrappermode = yes, it refuses to connect to the new server. If I do set it, it refuses to connect to the existing ones. There are some hints in the documentation that you can use transport_maps in some way, but I can't figure out how.

Spent the morning trying to figure out why recipient_delimiter = + wasn't working in my postfix/dovecot/mysql/ldap setup wasn't working. Yes, it's a bit too complex for its own good, but I found it was a simple issue. [1/3]

Finally gave in and wrote some Postfix rules to route SMTP traffic for *.outlook.com hosted domains (basically any school or government I email) through IPv4 instead of IPv6 to stop being blocked by Spamhaus false positives on "my" shared v6/64. #IPv6 #SpamHaus #Postfix

SSL-Cert zu alt???

https://philos.fkn-systems.de/display/39663759-1168-31f2-8a81-01a987759740

Well, this blows. Spamhaus has blocked the entire 2600:3c00::/64 IPv6 range, which includes my email server. That seems a little excessive.

I found out because I tried to send an email to my employer, and they use Spamhaus. This is a problem for me and I'm not sure what to do. Maybe I can disable IPv6 for sending email. I dunno.

https://check.spamhaus.org/results/?query=2600:3c00::f03c:94ff:fe85:b6ee

Y-en-a-t-il parmi vous qui ont mis en place dans #postfix un système de liste blanche de correspondants par utilisateur.

On a des clients qui utilisent Mailinblack et qui apprécient le système de captcha envoyé automatiquement en réponse aux expéditeurs inconnus.

Il doit y avoir moyen de faire quelque chose de similaire avec milter et/ou sieve

Nos boites mails sont administrées avec ISPConfig

Just going through the logs of my own mail server (Thanks, @mwl !) to extend my #postfix #fail2ban #regexp to ban hosts with too many unsuccesful login attempts. Knowing the user name pattern (example.com only letters, others with at least one dot) I came up with

'warning: .*\[<HOST>\]: SASL LOGIN authentication failed: .*sasl_username=<F-USER>(?:[^.]*@(?!example\.com)|[^.]*\.[^.]*@(?:example\.com))</F-USER>'

This works great.

Whilst migrating from my very manual email setup to something orchestrated by ansible and highly-available, I have come upon all sorts if jankiness I don't remember configuring.

Currently, I have multiple working MX servers, but only one postfix submission server. The MX's currently all point to a single dovecot server for LMTP, and it also pulls double-duty as my IMAP server.

Next on my list for ansible configuration:

• Set up acme.sh so that each MX can handle its own certificates for postfix and dovecot
• Configure Submission, LMTP and IMAP
• Configure extra mail services, such as opendkim, opendmarc, spf checking, dovecot indexing

This has been a real learning experience, and with any luck will get me to the point where I'm able to spin up/down new mail handlers just by adding hostnames to an ansible inventory list.

I find it really sad that Trusteddomainproject (authors of OpenDMARC) is basically dead