Unanswered Questions

1,333 questions with no upvoted or accepted answers
13 votes
1 answer
7k views

Change Envelope From to match From header in Postfix

I am using Postfix as a gateway for my domain and need it to change or rewrite the Envelope From address to match the From header. For example, the From: header is "[email protected]" and the Envelope ...
5 votes
0 answers
460 views

Postfix: do not create bounce message for virtual_alias_maps with remote servers

I am using virtual_alias_maps to forward mail to remote mail servers (GMail, icloud). I have spam prevention in place myself (SPF checks, Before-Queue Content Filter etc), but often enough spam will ...
5 votes
2 answers
3k views

How to log the whole SMTP session including DATA with postfix?

I am running a Debian 8.5 with postifx 2.11.3-1 and i try to log the whole smtp session including DATA to mail.log. it was possible to see a part of the data by increasing the verbosity by adding -...
5 votes
2 answers
682 views

PAM vs /etc/shadow in Dovecot SASL configuration - Security differences?

I set up a server with Postfix SMTP auth through Dovecot SASL. However, it was not possible to get the PAM authentification working as standard out of the box. So more by chance, I changed it to ...
4 votes
0 answers
1k views

Ways to integrate incoming and outgoing mail webhook in Postfix

I am trying to build an application in PHP which will be able to create a Ticket whenever a new mail arrives on a specific account and whenever a reply is done for that email, the application will ...
4 votes
0 answers
2k views

Disable bounce in Postfix after failed mail forwarding

I have some mailboxes in Plesk/Postfix that redirect to some external addresses. If Postfix fails to forward a message to these addresses, it bounces back to the original sender, who is a fake address ...
4 votes
0 answers
965 views

Postfix failed SPF check

I'm using postfix to send mail from my own domain and postfix-policyd-spf-perl to check SPF. SPF check fail only when I send an email from my own domain to my own domain. In summary : mydomain -> ...
4 votes
1 answer
3k views

When does Postfix not perform lookups in virtual_alias_maps?

I'm having a real pickle of a problem: I have a Postfix 2.6.6 / CentOS 6 server that's set up to forward mail from specific aliases to specific destinations. This is done through a mysql ...
3 votes
0 answers
389 views

postfix smtpd process bound to unix domain socket

To utilize a special cleanup daemon for outgoing emails only, I defined a special smtpd process in master.cf that is used as default_transport. (Only postfix should be able to submit emails through ...
3 votes
1 answer
221 views

What is current advice on forwarding email - particularly to gmail

I want to move from my current hosting site to a VPS. I am very comfortable with the website hosting side of things but at the moment my stumbling block is email, something which I have never had to ...
3 votes
1 answer
395 views

Remove unnecessary quotes from sender display name with special characters

I have set up Postfix with Dovecot and SquirrelMail on an Ubunutu 18.04 machine. Everything is working great, except for the display name with special characters. In SquirrelMail, I have configured ...
3 votes
0 answers
11k views

Sender address rejected: Access denied (in reply to RCPT TO command))

My email server has been ok for months now, since today my server would not receive any emails, I could send though. I seem to have fixed that by disabling and enabling UFW, not sure why that works ...
3 votes
0 answers
631 views

Postfix: Enforce sender address for some users only

I am looking for an option to enforce an envelope sender address in postfix for selected users, only. E.g., I want to permit [email protected] to send mails as [email protected], only, while all other ...
3 votes
1 answer
758 views

Hosting multiple websites (Apache Virtual Hosts), Postfix settings for sending mail FROM those domains?

I am not sure that this was the right solution in the first place but I have Postfix up and running on my Ubuntu VPS with G-Suite using relayhost = [smtp.gmail.com]:587 Mail is delivering fine, ...
3 votes
0 answers
494 views

Stop postfix from sending non-delivery notifications when forwarded mail bounces

Some of my mail users are forwarding their mails to gmail for example. In some cases my Amavis lets some spam messages slip through. These mails are then bounced by gmail as they are spam. My postfix ...
3 votes
0 answers
986 views

Don't send outgoing mail via Spamassassin

My e-mail server is running Postfix 2.11.3 on Debian 8.7 (Jessie) with Spamassassin 3.4.0. I realized that my outgoing e-mails are also being checked for spam, which not only seems to be unnecessary ...
3 votes
0 answers
358 views

Postfix: Avoiding backscatter when acting as backup MX with unknown valid recipiants

I'm running Postfix 3.1.0, acting as backup MX (i.e. I have relay_domains set) for a domain whose valid recipients I cannot practically know. Thus, I would normally be producing backscatter when I ...
3 votes
0 answers
5k views

Change FROM Name with Postfix

Using Postfix on Ubuntu 16 with google smtp server. Everything works fine. The only problem is that I can't seem to find out how to change the FROM name in postfix. I have rewritten the email ...
3 votes
0 answers
435 views

Prevent misdirected bouncebacks from forwarding server

Note: This question is a duplicate of Avoid creating backscatter on a Postfix forwarding server, for which the only answer was "sorry, nothing you can do", but I provide more detail here, consider ...
3 votes
0 answers
4k views

SSL_accept error with postfix oportunistic STARTTLS

I have configured postfix 2.6.6 on centos 6 as a mailrealy in front of an exchange 2010 server. Things work. Now I would like to add oportunistic encryption to incomming and outgoing mail. At least ...
3 votes
0 answers
191 views

Postfix STARTTLS works in LAN but not externally

if I connect in LAN on port 25 to my mail server, it offers STARTTLS telnet mailserver.com 25 Trying 192.168.0.x... Connected to mailserver.com Escape character is '^]'. 220 mailserver.com ESMTP ...
3 votes
0 answers
1k views

Configure mailgun as relayhost on top of existing postfix server already using sasl

I might be barking at the wrong tree completely here, but I'll ask anyway. I've followed a tutorial to setup a Mailserver on ubuntu 14.04 with postfix, dovecot and mysql. Now I have setup mailgun to ...
3 votes
0 answers
552 views

I need help trying to authenticate with AD from my linux machine

I am not experienced in this, so there might be some points that I am missing. Initially I tried to setup Cyrus Mail w/ SASL for AD authentication. After several tries, it failed to work. I switched ...
3 votes
1 answer
9k views

postfix: lost connection after CONNECT/EHLO/unknown from unknown

seeing following error message while trying to send email via postfix on Centos 7 while I can receive and download messages not seeing any errors postfix/smtpd[24532]: connect from unknown[5.31.230....
3 votes
0 answers
282 views

Postfix relaying for multiple domains with Amazon SES

I'm a little confused about relaying with Postfix. I added this line to my /etc/postfix/transport mydomain34.com smtp:email-smtp.us-west-2.amazonaws.com I know this is wrong, but this is what I ...
3 votes
0 answers
951 views

Unable to send email via Postfix SMTP via Mac Mail App

I installed a SMTP server with Postfix as mail agent (on Ubuntu 12.04). Config is as follow: $ postconf -n alias_database = hash:/etc/aliases alias_maps = hash:/etc/aliases append_dot_mydomain = no ...
3 votes
1 answer
24k views

Postfix / smtpd_relay_restrictions. How to allow relay from third party smtp server to any domains (but not open relay!)

By default, my Postfix allows relay emails sent to my domain (domain1.com) or only for password auth clients or for 'myhostname' addresses. This is a regular situation for most mail servers. If I set ...
3 votes
1 answer
3k views

Make Postfix search LDAP group members by UID instead of DN?

I'm creating an e-mail server with postfix (v2.7.1 on Debian 6.0) where users and groups are stored in an LDAP server. Users accounts works fine but I want to create e-mail aliases from group (any e-...
2 votes
1 answer
102 views

Postfix: How to log to syslog only?

I have Postfix 3.8.1 on Ubuntu 23.10. How do I configure Postfix to log to syslog only? My syslog daemon is journald. According to my understand, Postfix should log to syslog, if maillog_file is not ...
2 votes
0 answers
54 views

Docker Postfix Admin bulk aliases, custom maps, and custom config files

I'm in the process migrating my bare metal postfix implementation over to docker to essentially upgrade my old box to a more docker/vm-centric server and hopefully add virtual domain support. I'm ...
2 votes
0 answers
150 views

need help to configure postfix / dovecot + SSL for ports 993, 465 + virtual mail/accounts from file + CRAM-MD5 authentification

I have some issues in my configs to have an full functional mailserver with CRAM-MD5 authentification for only port 993 and 465. Plz help me and others to get an right config file struct for ubuntu ...
2 votes
0 answers
110 views

Dovecot trying to authenticate external users

I am using dovecot version 2.3.4.1 with SQL authentication and it works perfectly fine. I see in the logs though that when I use a PHP script to email a list of users, that dovecot is trying to ...
2 votes
0 answers
85 views

suspicious postfix warnings

I am running a private mailserver for quite some time now, which is a postfix / dovecot setup. I noticed some log messages from postfix, which alerted me a little bit, and I hope, someone can explain ...
2 votes
0 answers
276 views

OpenDKIM on MTA not signing mails from remote mail servers

I have a configuration where we have one MTA responsible for sending emails from a number of internal servers. The internal servers all run Postfix on a number of different domains. They are all ...
2 votes
0 answers
143 views

Postfix inline regexp lookup table

According to the manual regexp_table(5) section INLINE SPECIFICATION there is a possibility to write the regexp lookup table inline. INLINE SPECIFICATION The contents of a table may be specified in ...
2 votes
0 answers
246 views

Postfix SASL error: warning: unknown[xxx.xxx.xxx.xxx]: SASL LOGIN authentication failed: authentication failure

My use case is to use my own mail server to send emails from CCTV NVRs to overcome the daily limits imposed by GMail. The NVR has an option to setup authentication. The config worked for whitelisted ...
2 votes
0 answers
963 views

Is it possible to use MTA-STS in Postfix without overriding DANE?

The SMTP MTA Strict Transport Security RFC 8461, 2 clearly states that: However, MTA-STS is designed not to interfere with DANE deployments when the two overlap; in particular, senders who implement ...
2 votes
1 answer
779 views

How do I tell Dovecot to use another server for SMTP?

I am a bit lost on mail servers, but I have to install a mail proxy (Proxmox Mail Gateway) in front of the actual mail server (ISPConfig, Roundcube, Dovecot, Postfix). On receiving emails, it uses the ...
2 votes
0 answers
496 views

Postfix email not send from subdomain

I have setup email server on ubuntu with Postfix, roundcube, powermta. mail server domain: mail.example.com emails are working fine when I test with gmail. I have installed mautic on another subdomain ...
2 votes
0 answers
276 views

TLSA lookup error for dhmx02.web.de:25

we are running a mail server and always the same error in the logs (for a specific recipient): Aug 23 05:39:17 Mailer postfix/smtp[13561]: warning: DANE TLSA lookup problem: Host or domain name ...
2 votes
0 answers
1k views

postfix/sendmail can't read main.cf file

I'm trying to configure a mailserver, but when i run: echo "test email" | mail -s "test" [email protected] -aFrom [email protected] and check tail /var/log/mail.err I get Aug 8 ...
2 votes
2 answers
1k views

SELinux - blocks postfix emails sending out from the Web Application

My System environment, is Centos-7.9, Apache2.4, Php-fpm, PHP-7.4 I have postfix setup to send emails from the website, which is working in stand-alone test emails and when I turn the SELinux off. ...
2 votes
0 answers
154 views

How to avoid Postfix sending emails without authentication even to users of the same domain

hopefully you could help me. I just installed postfix and I am trying to configure to avoid spam. The version I installed is 3.4.14 I am trying to configure posfix to have this behavior: From External ...
2 votes
0 answers
500 views

I'm looking for a way to configure distance clustering of postfix and dovecot

I currently have a postfix server and dovecot server sharing files from an NFS server in the UK and the same config in Switzerland. I tried to mailsync but that appeared to lose emails, so then I ...
2 votes
0 answers
689 views

How does Postfix define an unlisted recipient or sender?

Postfix's documentation defines smtpd_reject_unlisted_recipient (default: yes) as Request that the Postfix SMTP server rejects mail for unknown recipient addresses, even when no explicit ...
2 votes
0 answers
998 views

GMail not receiving email sent via PostFix

I have a VPN configured with Plesk. (I have installed a SSL/TLS certificate, through Plesk, using Lets Encrypt. Everything seems good as far as I can tell, but I mention it as it also protects emails.)...
2 votes
0 answers
463 views

Postfix bounces incoming emails with uppercase recipient (unknown user)

I just installed Postfix on Debian minimum server and configured it as below: installation: installed it chose internet site set name to mydomainname.com /etc/postfix/main.cf configs: changed ...
2 votes
0 answers
226 views

How do I tell Postfix 'edge' MTA to fake it's a final destination for DSN?

My question is regarding the Delivery Status Notification (DSN) handling of my inbound Postfix mail server instances. The solution to this may be completely outside of scope of DSNs however. Let's say ...
2 votes
1 answer
909 views

postfix won't send mail via Amazon SES - Host or domain name not found

I have been trying to configure my Amazon EC2 instance (running Ubuntu 20.04) to send mail via Amazon SES. I have various settings I've borrowed from an earlier (successful) configuration to prevent ...
2 votes
0 answers
371 views

E-mail body changed after DKIM signing

I've got a postfix e-mail server which uses amavisd-new for virus scanning, spam checking, DKIM checking and DKIM signing. I'm having issues with the DKIM signing in particular. Amavisd-new signs the ...

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