All Questions
955
questions
1
vote
1
answer
39
views
Postfix connection timeout to all servers
I have Postfix on an Ubuntu server.
postconf mail_version
mail_version = 3.6.4
Every email i send to any recipient ( tried gmail , hotmail and yahoo ) , is stuck in the queue
(connect to alt2.aspmx.l....
- 11
1
vote
2
answers
117
views
How can I mitigate a flood of inbound emails that look legitimate to filters?
I have a mail server - postfix, amavis, dovecot. Currently one of my inboxes is being flooded with random email from all over the globe. It's like someone signed me up to 10,000 newsletters all at ...
- 125
0
votes
0
answers
31
views
Postfix replace in body by adding CR
I'm trying to configure Postfix body_checks function in order to add a CRLF when an end of attachment is detected using this:
/(.+)--$/ REPLACE $1--\r\n
The regex is correctly applied but the \r\n is ...
0
votes
0
answers
18
views
How to change the sender address using mailutils and postfix?
May 27 14:19:33 localhost postfix/qmgr[21793]: 87FD870AD12: from=user@localhost,
size=398, nrcpt=2 (queue active)
May 27 14:20:03 localhost postfix/smtp[22591]: connect to
mail.rungel.net[95.168.160....
0
votes
2
answers
272
views
554 5.7.1 Relay access denied - cant send mails
I tried to upgrade debian from 10 to 11 and the everything got messed up. Im trying to fix postfix. I can receive emails but cant send. I get the error "554 5.7.1 Relay access denied"
My ...
- 11
0
votes
0
answers
47
views
How to add your own private keys to postfix configuration for DKIM without opendkim or the likes of it?
I have generated the keys locally through openssl added key.pub to the DKIM DNS txt Record but how to add it to postfix withouth any other tool.Is there any connfiguration parameter where the file ...
0
votes
1
answer
155
views
SMTP Server: Postfix w/ Dovecot - how to configure the allowed username + password?
I seek a Linux-based SMTP server.
I've read tutorials and specs regarding Postfix SASL with Dovecot, though I can't find how to configure the list of username and password which are allowed to send ...
- 175
1
vote
0
answers
94
views
How can I make MIAB automatically copy all mail sent via SMTP into the sent folder of the sender's account?
I run Mail-In-A-Box on my mail server and one of my clients is using a specialized application to send messages via SMTP from their account on my server. When they used their own Gmail account to send ...
- 11
0
votes
3
answers
262
views
Postfix sending duplicate emails under different userid's, how to fix?
I can't find a reason for it in the postfix settings, but duplicate emails are being sent, under different uid's. Looking at the email headers, they have unique ids, and each with a different Postfix, ...
- 111
1
vote
1
answer
118
views
Postfix - can't limit active queue
One of the destinations I send email to has unusual performance characteristics. The active queue can fill up with messages for this domain, blocking sending to other domains. I want to limit the ...
- 22.7k
0
votes
0
answers
64
views
postfix MTA seemingly benign I/O Error : postqueue fatal: output write error: Input/output error
I am getting the following message in my syslog exactly every 30 seconds. Everything is working but words like "Fatal" and "Input/output error" cause me an inordinate amount of ...
- 21
0
votes
1
answer
49
views
How to send email from smtp server1 to smtp server2 (Postfix) via client?
How to make server1 with postfix can send email to server2 with postfix by redirecting DNS query to it (type forward). These servers are on the same local network. Server1 is to receive a non-...
- 1
0
votes
0
answers
106
views
Postfix/Dovecot fails to send emails "SASL PLAIN authentication failed" - no further message
I have been all around the houses trying to configure Postfix and Dovecot so I can send through my domain from Gmail, which as far as I know is simply Gmail acting as a regular SMTP client talking to ...
- 235
0
votes
2
answers
181
views
How to change the sender / from field using Postfix as SMTP relay server to relay to MSO365 mailbox
My company have set up an Ubuntu 22.04 Server to act as an SMTP relay server to relay messages to our Exchange online mail server.
A user account [email protected] has been setup on the Exchange to be ...
0
votes
0
answers
150
views
Failed to send SMTP email with PowerShell and Postfix SMTP relay
I tried to correct some errors with a PowerShell script with Send-MailMessage() that sends an email via a Postfix SMTP relay, but it returns this error:
error PowerShell
I found that I should add this ...
0
votes
1
answer
153
views
Postfix to not delivery mail to domains using another mail server
I am configuring a hosting + mail setup. I have one server for hosting websites, and one for the smtp/imap/dovecat server.
As far as I researched, the only reasonable way to allow my customers to have ...
0
votes
0
answers
145
views
Is possible to use a DKIM-Proxy to signing emails requested from another application?
I using an application to send emails, written in golang which use net/smtp as SMTP Libary, however that lib provide no support with DKIM signing, but using a sendmail command, for example, the DKIM ...
0
votes
1
answer
140
views
POSTFIX smtpd relay depending on sender
I am using Postfix on a server mx1.domain1.com to relay e-mails for domain1.com as well as other domains, domain2.net, and domain3.org, which are hosted on the server (domain1.com). In addition, mx1....
0
votes
2
answers
102
views
In Postfix, Should SSL FQDN Matches with myhostname or mydomain field in /etc/postfix/main.cf?
Quoted from the documentation:
myhostname
The internet hostname of this mail system. The default is to use the fully-qualified domain name (FQDN) from gethostname(), or to use the non-FQDN result ...
- 203
0
votes
1
answer
185
views
Warning: you may need to increase the main.cf smtp_destination_concurrency_limit - but it is set?
We have a huge delivery of emails right now and emails are not delivered as fast as I think they would:
In the mail log (Postfix v3.4.13 ) I see the following message
Dec 8 14:34:28 s29 postfix/qmgr[...
- 198
0
votes
0
answers
168
views
PAM failing to authenticate all users from one domain in dovecot
I have installed a mail server using Dovecot + Postfix, and it always worked correctly.
Recently I installed a new domain example.com and a user [email protected] for that domain in the mailserver ...
0
votes
0
answers
308
views
Can not setup postfix/dovecot with email clients
Having problems with configure postfix/dovecot with email clients such as outlook and thunderbird.
Using telnet and openssl I have tested both smtp and imap through ports 587 and 993.
Sent mails are ...
0
votes
1
answer
222
views
Rewriting message header To: field when sending email
I am configuring an SMTP server with Postfix (v3.7.3) for local (i.e. host only) mail sending on openSUSE 15.5 Leap.
What I would like is to send messages to local "users" (there is no real ...
- 1
0
votes
0
answers
256
views
stunnel smtp tls frontend server/proxy for remote backend postfix
I'm running stunnel in server mode and listening on port 587 and trying to connect to a remote postfix server running on port 25.
NB: the two servers are connected via zerortier, which may or may not ...
google-cloud-platform
0
votes
2
answers
495
views
Can I Force Implicit TLS Connection For Port 587 On Postfix?
I have read many articles saying port 587 by default is explicit TLS. This means it's STARTTLS. It asks the server on an unsecured connection if TLS is supported and if it is, it continues with an ...
1
vote
1
answer
255
views
Wrap plain text mail in html
we use Postfix as MTA to send our mails from our system. Unfortunately we have an old persistent system which we cannot change, which sends mails to our customers in plain text format. I would like to ...
- 15
0
votes
3
answers
148
views
Postfix: How can I handle incoming mail for a single address, not the entire domain?
I've gotten my employer to configure the company-wide Exchange server to forward [email protected] to [email protected], a host I control. So far, so good. My Postfix configuration ...
- 131
0
votes
2
answers
3k
views
Postfix relay to Office 365 - DNS configuration
To reduce the likeliness of email being flagged as SPAM, I believe these are the few things that should be done on email servers:
Hostname resolves to a valid IP e.g. mail.example.com to 1.1.1.1
...
- 359
0
votes
0
answers
21
views
Postfix 2nd domain
I have two postfix servers(virtual machines) on same host
1st domain = mail.xyz.org
2nd domain = mail.xyz.edu
I want to send mail from 1st domain to 2nd domain.
If i try, it gives error:
Recipient ...
- 1
0
votes
1
answer
517
views
How to configure postfix to reject emails which are pretended to be send from myhostname?
Suppose the Postfix mail service is serving domain @mycompany.com. Local network is 192.168.10.0/24. The attacker from Internet sends an email pretending it originates from @mycompany.com:
Received: ...
- 123
0
votes
2
answers
914
views
Postfix smtpd_sender_restrictions with logical AND
I am using postfix, I need to configure sender based restrictions so nobody that is not authenticated & not part of mynetworks can send mail through this server,
this is my smptd sender ...
- 101
0
votes
1
answer
417
views
Postfix header_checks are ignored
I'm using Ubuntu 20.04. I installed Postfix (v3.4.13) with Dovecot (v2.3.7.2) a long time ago. Now, I want to overwrite the Message-Id header using header_checks. It's the first time I'm trying to use ...
- 1
0
votes
0
answers
189
views
Postfix - forwarding mail to an external email address
I'm not normally a Linux server guy: I'm a .NET programmer. However, I inherited a situation where there's a website hosted on a Linux server using Postfix on Webmin. They have several aliases set up, ...
- 1
0
votes
1
answer
273
views
POSTFIX - sending mails. My mails sent outside bounce back
main.cf
compatibility_level = 2
command_directory = /usr/sbin
daemon_directory = /usr/lib/postfix/sbin
data_directory = /var/lib/postfix
mail_owner = postfix
myhostname = mail.aufy.pl
mydomain = aufy....
- 13
0
votes
1
answer
1k
views
How to set up a postfix relay server for Google Workspace(gmail)?
There is a need to make a relay server for the company's corporate mail. The need arose due to the presence of some google ip in the spam lists, and this sometimes leads to the fact that letters end ...
- 1
1
vote
0
answers
281
views
Not receiving any response from SMTP server after successfully connected via openssl or telnet
I am trying to set up my postfix using Gmail smtp relay server. I have set it up in other servers without issues, but I am having difficulty getting it to work in my work network.
I tested if there is ...
0
votes
1
answer
490
views
Postfix - Relay - authentificatin in Mysql
I tryed to manage with a postfix server, my goal is that :
When 1 special user ([email protected]) try to send mail, it will use routing (using a relay server is OK) but I don't understand how to send ...
- 1
0
votes
1
answer
170
views
Postfix to gmail relay - preserving the sender's address
Relayed emails come 'from' [email protected], not [email protected], so I cannot reply.
I have several domains and am using Postfix to relay emails sent to [email protected] on to [email protected] as ...
1
vote
1
answer
2k
views
how to switch from outgoing port 25 to 587 in postfix
I would like to send a mail to a gmail address:
echo "This is the body of the email" | mail -s "This is the subject line" [email protected]
That is what I see in the logs
connect to ...
- 145
0
votes
1
answer
450
views
iptables - port 25 not getting traffic even though default policy is ACCEPT and all rules are flushed
I am having a problem that's driving me up the wall. I have a server, where after several attempts at various iptable rules, I have flushed iptable rules and set default policy to accept.
The output ...
- 121
1
vote
1
answer
398
views
Postfix/Dovecot - Initial Config - Test Email Results - 554 5.7.1 Client host rejected: Access denied
I sent an email successfully. Can't say the same for receiving. When I attempt to, I get an email saying that the message was blocked with the following diagnostic code:
Diagnostic-Code: smtp; 554 5.7....
0
votes
2
answers
3k
views
What exactly is Return-Path and who sets it?
This article (https://www.sparkpost.com/resources/email-explained/return-path-explained/) explains "Return-Path" as follows:
When an email doesn’t make it to its intended destination, the ...
- 101
1
vote
1
answer
646
views
Postfix white listing a badly configured server not working: Helo command rejected: Host not found;
My mail server configuration is rather strict and some times incoming mails from legit servers get rejected because the remote end has a configuration problem, a common one is the HELO hostname.
I ...
- 63
1
vote
0
answers
398
views
Configuring postfix to use SendGrid SMTP relay with fixed FROM address but need to append REPLY-TO of original sender
I have been trying to resolve for a couple of months using multiple different configurations.
The local delivery to a Dovecot mailbox ([email protected]) keeps the original sender (sender@gmail....
- 11
0
votes
1
answer
137
views
Postfix: different smarthosts per server port
I need to install Postfix and let it listen on two different ports: 1025 and 1026:
/etc/postfix/master.cf:
1025 inet n - y - - smtpd
1026 inet n - ...
- 1,913
1
vote
1
answer
8k
views
Postfix "Client host rejected: Access denied" how to diagnose the precise reason?
I see this question asked over and over on serverfault, and each time it seems to accompanied by a copy of the configs and result sin a successful or not diagnosis by wonderfully helpful readers.
I ...
- 181
1
vote
1
answer
146
views
postfix logs showing ??? as command from client
I am running an Ubuntu 18.04.6 LTS server with the postfix 3.1.0-3ubuntu0.4 package.
Both the Apple Mail client and the Postbox client experience a weird delay when first sending an email to the smtp ...
- 195
1
vote
0
answers
152
views
Relay Host change
I have example.com configured as using relay mailjet.com and also the emails associated with that like [email protected] would like this [email protected] to use another relay which is ...
- 19
1
vote
0
answers
115
views
Before-queue Content Filter won't inject data back to Postfix
I have been building a before-queue filter with Postfix on NodeJS to retrieve the data from outgoing mails, remove the attachments, upload them on a CDN and inject back the URLs in the outgoing mail.
...
- 11
0
votes
0
answers
211
views
postfix-How can I discard emails without message-id?
Some users send smtp emails by postfix.
But there emails have no header Message-ID.
I want to reject them or discard them.
I tried to modify header_checks, but the file filter headers line by line.It ...
- 1