Questions tagged [smtp]
SMTP is the Simple Mail Transfer Protocol, the most recent standard of which is defined in RFC 5321. It's the Internet standard for sending and receiving email.
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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-...
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Changing sendmail HELO/ELHO header in docker container
I have a Debian 11 docker container in which sendmail v. 8.15.2 is installed as MTA. Unfortunately spamhaus.org blacklisted the host IP due to the HELO header of mails being sent from this container ...
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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 ...
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Telnet SmarterMail: 550 This is a submission only port. You must authenticate before sending mail
I have a "newer" server running Windows Server 2019 and I installed Smartermail FREE Edition so I could send mail via PHP/CDONTs from contact forms to my email address.
I tried matching the ...
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If a lower priority mail server only serves code 450, will sending servers on retry use a higher priority server?
I had a backup mail server eat a bunch of messages and I want to just configure a simple server to send 450 for all messages.
However, I'm not sure this is a good idea because if the sending servers ...
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Outlook getting spurious SMTP errors when connecting to Linux dovecot mail server
I'm running a mail server for about 30 people. I have had zero issues with it. But last week, several users began reporting an error in their email client, Outlook:
Checking the server mail log ...
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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 ...
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Why Google SMTP MTA's are not sending STARTTLS command
I'm a software engineer that wrote my own SMTP delivery agent. I recently added the STARTTLS support to my software and I was doing some testing, when I noticed that Google's SMTP transfer agents are ...
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How to use NGINX as legacy SMTP proxy to new SMTP system?
We have some very old radio equipment in the field which uses SMTP to notify us of failures. Unfortunately this equipment does not support modern SMTP authentication methods (SSL, etc), and can only ...
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Original DKIM signing is not sent when using SMTP relay
We are using a VPS (ubuntu 18, postfix) to send mails for multiple domains hosted on a server (AlmaLinux 8). For example from the domain "domain.com".
VPS is maildomain.com
Hosting server ...
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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 ...
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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 ...
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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 ...
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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....
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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 ...
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