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Questions tagged [mail-transport-agent]

To be used with questions relating to a Message Transfer Agent also known as Mail Transfer Agent (MTA) or mail relay.

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How can I make GNU mailutils to use an external SMTP server?

Does anybody on this planet know what the equivalent GNU mailutils command to the following looks like? Is this even possible without a local MTA with mailutils? Using s-nail it works as intended. s-...
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1 vote
1 answer
106 views

During email delivery, how do MTA, MDA, POP/IMAP connect with each other?

I have already read Why use Dovecot AND Postfix/Sendmail?, Why use both Dovecot and Postfix?, Why use both Dovecot and Postfix? which give the general idea, but here I'm looking for more precise ...
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0 votes
1 answer
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Send cron mail using dockerised postfix

I recently moved postfix into a docker container, with ports 25 and 587 exposed on the host machine. Since doing this, cron on the host machine is now unable to send emails due to No MTA installed, ...
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1 vote
0 answers
53 views

replace MTA with something not email related

What I try to achieve is to send all my server logs, errors, crontab outputs etc. with something like telegram or signal. I am locking for a MTA with can handle a different backend and is still ...
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0 answers
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sendmail: Using alternative port with smart-host

Sendmail not following smart_host alternative port macro. Using Exchange server, exchange.redacted.com, we are using port 2525 for internal devices and some Linux based machines, allowing them send ...
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-3 votes
1 answer
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Why is the email sending process not symmetric with the receiving process?

Reading https://ccm.net/contents/116-how-email-works-mta-mda-mua and https://en.wikipedia.org/wiki/Email_agent_(infrastructure), I wonder why the email sending process is not symmetric with the ...
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0 votes
1 answer
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block IP or spam or another problem

I setup an SMTP server(Postfix), Then I send an email to my gmail, I get the following email from gmail: This is the mail system at host mail.pahlevanzadeh.net. I'm sorry to have to inform you that ...
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0 votes
1 answer
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courier-mta (esmtpd) only delivers messages to /var/lib/courier/tmp

I swear that courier-mta was working before, but now it has stopped working. The problem first started out with getting "submit: Permission denied" errors and I was unable to send emails to the ...
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4 votes
2 answers
1k views

What's the difference between an MTA and SMTP server?

Take postfix for example. It's an MTA, but is it also an SMTP server? Are all MTAs SMTP servers? Are any? Is there a difference between a mail transport agent and a mail transfer agent? Can an MTA be ...
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1 vote
2 answers
705 views

Exim4 and root aliases? Send a copy to root?

When setting up my raspberry pi to use local email (using exim4 as the default MTA on Raspbian/Debian), and while doing the debconf initial configuration, I was asked whether to forward root's email ...
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3 votes
3 answers
1k views

Why does cron use MTA to send emails, while we use MUA to send emails?

I have looked at the definitions of MTA, MUA, MDA, for example, https://ccm.net/contents/116-how-email-works-mta-mda-mua and https://en.wikipedia.org/wiki/Email_agent_(infrastructure) In Lubuntu, the ...
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0 votes
1 answer
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Exim and Spam Filtering

for years I've been using Exim as MTA. I had three strategies to prevent Spam. First of all blacklists. The second was to delay the mail delivery and the third was SpamAssassin. But this year, more ...
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0 votes
1 answer
73 views

Is there a Linux package on Ubuntu that offers a sendmail tool which can forward the message with SMTP or fallback to a file when SMTP fails?

I'm wondering whether there is a sendmail tool that would allow me to send emails without all the overhead we see in servers like Postfix. I use Postfix already, so I know how to set it up and all. ...
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0 votes
2 answers
421 views

How can I set up a local MTA on NixOS?

caff from nixpkgs.pgp-tools seems to require a local MTA to send keys with UIDs signed to the corresponding email addresses. (It uses perl's Mail::Mailer for that.) How can I set up a local MTA on my ...
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  • 409
0 votes
1 answer
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OpenSMTPD: every local mails to a specific destination

I currently use Exim for the following need, and it works well. But too much hassle when upgrading because this is a hack which require modifying files we are not supposed to. I try with OpenSMTPD ...
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0 votes
2 answers
308 views

What ports are advised to use for secure mail?

I have installed postfix and dovecot mail server. My clients use The Bat software to send/receive mails. They use standart 25 and 110 ports. Now I want to secure my connection, and I want to ask ...
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2 votes
1 answer
829 views

How does mail end up in /var/mail/<username>?

I've found plenty of information about where the mail comes from; typically cron scripts, but also things like apt-listchanges. I've found plenty of information about how to read the mail once it's ...
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0 votes
2 answers
365 views

postfix + procmail -- process serially, not in parallel

Trying to design a system that can filter incoming email messages from a syslog server. Need to drop if they appear to be duplicates (throttle them). Procmail pipes them to a perl script for ...
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2 votes
1 answer
57 views

Do two MDAs need their own MTAs?

Suppose I have an MDA in example1.com and an MTA in example2.com. Do I need an extra MTA on example1.com? MUA --- MDA --- MTA --- | Internet | --- MTA --- MDA --- MUA So far I used two MTAs.
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3 votes
2 answers
7k views

How to encrypt Postfix emails with SSL

I have 2 domains registered and MX records set up and pointing at the same server. The output from this tool https://mxtoolbox.com/SuperTool.aspx is 10 mail.mydomain.club IP 5 min 10 mail....
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1 vote
1 answer
586 views

What Mail Transfer Agents is PHP using?

I'm trying to diagnose a problem with certain email addresses possibly being blocked on my server. I'm running PHP 5.3 on CentOS 5.7. The php.ini file lists a sendmail_path of /usr/sbin/sendmail -t -i,...
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  • 191
1 vote
1 answer
589 views

Using a custom filter via script to reject inbound email

Background & Requirements I've found a number of reference docs and Q&A post relating to this topic but I've not been able to figure out a key area of the design. I would like to reject an ...
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5 votes
1 answer
1k views

msmtp Empty TO and FROM Field - All mail ends up in Bulk Mail when sent from CLI or manually

I have set up MSMTP with the following but if I send an e-mail from the CLI it either gets blocked, or ends up in my SPAM because it has no TO/FROM or anything up top. But e-mails from CRON are ...
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0 votes
1 answer
2k views

Hetzner sendmail problem "return to sender: User unknown" [closed]

for some reason my sendmail is not able to send mails from my virtual server at Hetzner via sendmail. In my /etc/mail/aliases config look like: mailer-daemon: postmaster postmaster: root nobody: ...
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1 vote
2 answers
2k views

nullmailer: Sending failed: Could not exec program

I'm trying to set up nullmailer with Google Apps. I think I have properly configured Google Apps and /etc/nullmailer/remotes, but somehow I'm getting this error Sending failed: Could not exec ...
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3 votes
1 answer
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What should I configure to send mail on the command line?

I am working in the computer at home I want to send me an email and I tried: uuencode all.sh all.sh | mail mymail@gmail.com But the problem is that nothing arrive to my email, I just get the ...
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4 votes
0 answers
340 views

Examples of (not recommendations for) Message Submission Agent (MSA) software

From the Wikipedia articles email and email agent, I gather that there exist software packages known as message submission agents (aka mail submission agents). The Wikipedia article on message ...
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2 votes
0 answers
227 views

MTA with local delivery and per user smarthost

I have some problems choosing and configuring an MTA for my desktop system. Some tools like apt-listchanges or cron rely on local mail delivery and I think having local mail delivery available is a ...
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8 votes
4 answers
3k views

How to check if my e-mail goes to recipient's spam folder? [closed]

I'm using Exim as an MTA to send emails. Is it possible to get notified if an email goes into the recipient's spam folder?
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0 votes
1 answer
500 views

How can I display the last message in exim4 mail queue?

How can I display the last message in exim4 mail queue? I, actually, want to get the last message ID in exim mail queue, to check if it's delivered, in the log file.
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0 votes
0 answers
423 views

Email generated with Python stuck in mailq, times out (Debian)

I want to send emails out, originating from my Debian computer. I do NOT want the emails to originate from my gmail account, like in most Python smtplib examples. I called my ISP regarding port 25, ...
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4 votes
1 answer
4k views

How to enable secure authentication (ssl,tls,starttls) in nullmailer 1.0.5. and upgrade nullmailer to 1.11

I am using a linux based device where we use nullmailer to send email using smtp. nullmailer version: 1.0.5 User-Agent: Mutt/1.5.19 (2009-01-05) In the existing mechanism, our smtp server does not ...
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1 vote
1 answer
1k views

What MTA to use to deliver locally-generated mail only on debian?

Basically what i'm looking for Locally generated mail to local users is forwarded to some outside address Locally generated mail to remote domains is sent out directly to their MX servers (no ...
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1 vote
0 answers
159 views

How to rewrite an outgoing email address on the fly?

Follwing up on my question about headless and real-user-less setups, I am trying to find an alternate way of handling outgoing emails directed to local users (email outgoing from my machine rpi1....
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2 votes
0 answers
1k views

how to redirect all email to a single external address?

I have a headless server (rpi1.example.com) with two active accounts: pi and root. I would like all the emails sent to these accounts to be redirected to an external address: real@somewhere.net. ...
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1 vote
0 answers
334 views

Accept mails only for a certain address with Postfix

How do you configure a mail server to only accept mails on a certain address? For example, my mail server should only accept mail on example@myths.ops and not example@harpy.myths.ops. I've looked ...
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0 votes
2 answers
3k views

Should I ignore or totally block non-SMTP command attempts?

I have a couple of messages appearing in my Postfix mail logs every day, like: postfix/smtpd[7363]: warning: non-SMTP command from unknown[xx.xx.xx.xx]: GET / HTTP/1.0 Should I ignore them or block? ...
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0 votes
1 answer
391 views

exim + courier + squirrelmail mail delivery in wrong directories

I just installed an E-Mailserver using exim for SMTP, courier(-imap) for fetching mails via IMAPv4 and squirrelmail as web client for the end user. Everything works fine. But when I sent an E-Mail to ...
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4 votes
2 answers
2k views

Lightwight MTA which could listen on localhost port

I have multiple Ubuntu servers with Java applications running on it. One of the application's functions is to sent an email. Now we using exim4 as the MTA. I would like to replace exim with something ...
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1 vote
1 answer
8k views

mail command successful, but mail was not received by recipient

I used mail, its exit status is zero but the recepient is not receiving any mail. What could be the problem? I used this code: mylinsystem:/etc/mail # mail -v -s "test" test_user@receipient_domain....
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2 votes
2 answers
305 views

exim reject all local_part matching a pattern

I am trying to configure Exim to reject any $local_part that match a pattern. For example, I know that none of the local_parts for any of the myriad of domains I host will ever contains numbers. So, ...
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2 votes
0 answers
71 views

mailing thru ssh

(I am a Linux only user & MELT software developer, and use Linux since kernel 0.99.15 e.g. the previous century) I have a VPS host ovh.starynkevitch.net (running Linux) which is also the MX host ...
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3 votes
1 answer
17k views

How to turn off STARTTLS for internal relaying of emails?

I read with interest from sendmail guide that it is possible to disable TLS. I tried doing so for internal mails by adding the following lines in /etc/mail/access: Try_TLS:my.server NO ...
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7 votes
2 answers
48k views

Using port 587 with sendmail

I have been using sendmail to send out mails using internally available mail server. But currently port 25 is blocked for security reasons. I would like to know if there is a way to specify port ...
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  • 215
4 votes
1 answer
535 views

Change OS Name from email send by exim

OS: FREEBSD 9 OS ROLE: SERVER MAIL SERVER: EXIM When I send mail from my freebsd server to gmail. and when i click on show original. I shows my os name too along with mta name. as in first line of ...
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  • 498
0 votes
0 answers
626 views

How to Use Domainkeys and DKIM both with exim on freebsd server machine

I have setup exim mta on freebsd. I have also setup DKIM on this machine and my mails are properly signed. I want to know how to setup Domainkeys along with DKIM on exim so that my mails are signedf ...
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  • 498
1 vote
3 answers
4k views

Postfix, SMTP Server, PHPMailer

I have an PHP Forum (vanilla forums) and for its registration emails I installed Postfix. Now As I figured it out, vanilla forums uses PHPMailer for email sending procedure. Now my questions are: ...
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2 votes
1 answer
223 views

Restrict emails to system users in postfix?

I am running postfix, and it seems it is willing to accept emails for system users, such as man, sshd, daemon, www-data, ... Is desirable (probably not)? and what I can do to disable this?
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7 votes
2 answers
1k views

Debian: An MTA just to solve dependencies, not because I really need one

It has bothered me for years that with every new Debian installation, a full MTA (Mail Transport Agent) was installed even if I had no desire to use the machine as a mail server. The MTA was necessary ...
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