Questions tagged [email-server]

Refers to the hardware or software that make up a server dedicated to sending and receiving emails. Many popular modern email servers bundle other functionality for contacts and calendaring along email delivery.

Refers to the hardware or software that make up a server dedicated to sending and receiving emails. Many popular modern email servers bundle other functionality for contacts and calendaring along email delivery.

A list of mail servers can be found on Wikipedia, though sendmail, Microsoft Exchange Server, Postfix, and Exim are the most popular email servers, which together control over 85% of market share for SMTP service.

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postfix mail to relayhost gets bounced dsn=5.0.0: how to debug?

Postfix sends mail to relayhost, but relayhost bounces back with dsn=5.0.0 and no further details. Q: How can I debug this in detail so that I can find out where I made the mistake? Setup: smtp-client.test.com : this is a test server on which I…
terano
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Email proxy architecture

I'm trying to figure out how email proxies generally work. I want to present the way I see the architecture, would be glad if anyone could explain which of my assumptions is flawed and what am I missing. Assume I've purchased an email domain, let's…
Evgeny
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SPF Limits and SPF Merging

I am using Zoho Mail, AWS SES, GMAIL SMTP, Cloudflare email route and Yahoo SMTP. they all have there own SPF record. i saw on Google the only 1 SPF should be added in hostname and maximum 10 SPF hostname is supported in 1 SPF record. I am trying to…
Mehul Kumar
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Is it possible to run a mailserver on a nginx layer 4 server?

I've just created a layer4 nginx server, which is used as a load-balancer for a kubernetes cluster. I know it is a very basic question (and probably I'll get a lot of downvotes for this), but is it possible to install and run a mail-server on the…
user3142695
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Postfix with ISPConfig and `Sender address rejected: User unknown in virtual mailbox table;`

I have a mail server that was configured with ISPConfig (amavisd, spamassasing, dovecote, etc) and a few non-standard tweaks from the tool's default tutorial (ISPConfig). The server itself works beautifully. However, I have a problem delivering…
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How to trace/find "lost" emails with log files and doveadm?

One of my clients is missing some emails and I try to find what is going on, but my knowledge is limited. Have asked the server support guys, but they say all is fine and attach just the logs (which I can't read well > ♻️ ) What have I…
Sam
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Postfix doesn't run in macOS Ventura

I have just updated my Mac to macOS Ventura. When I try to start postfix, it says "$daemon_directory/master -t 2> /dev/null postfix/postfix-script: fatal: the Postfix mail system is already running". However with ps -ef | grep --color postfix I can…
Noah Wu
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Exchange 2016: high amount of send connectors problematic?

On an Exchange 2016 we would like to configure different security settings for approx. 250 Domains (Limit non delivery reports to these). A solution might be to configure a separate send connector for each of these domains. Is there a problem…
Wisseo
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setting up a mail server for my domain

Learning about how mailing works in general and I have the following question: If I own the domain bigmoon.com and I want to have a mail address that looks like bob@bigmoon.com, as I understand it I can do the following: Setup a mail server on a…
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Different DNS server answer me different things

I am having problem with email going to "jslawglobe.com". From certain email it always works. From others, it is a matter of luck. After investigating the problem with one of those sender emails from which it does not work: nslookup -type=MX…
serge
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How to prevent outgoing mails in postfix (or a mailcow instance)?

I want to use mailcow as an isolated mail server, so it's not supposed to send mails to the outside. The goal is to allow open registration on the mail server, and users should be able to communicate with each other - but I don't want to annoy the…
missytake
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Dovecot mail-crypt webmail can't read encrypted messages

I'm trying to setup Dovecot with mail-crypt plugin with per-user encryption. I have configured mail-crypt plugin as per official guide here: https://doc.dovecot.org/configuration_manual/mail_crypt_plugin/ After that I created a user and an encrypted…
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Spamhaus is blocking several customers since a couple of days?

I received a couple of complaints from customers that got their emails rejected. I haven't changed my config, so this must be an issue with spamhaus. I'm running Postfix with these settings for spamhaus: smtpd_sender_restrictions = [...] …
3und80
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How to test my postfix+dovecot setup?

I am creating one open source free docker mailserver at https://github.com/kristijorgji/docker-mailserver I have already some setup using postfix + dovecot + mysql for virtual users,domains but the problem is I don't know how to test the setup...…
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How do I get postfix to log the Helo/ehlo responses?

I need to get access to the Helo responses in order to make sure everything is set up correctly on the mail server.