Tag: postfix

postfix/submission/smtpd certificate expired alert number 45

I tried to configure Laravel mail client with secure connection via TLS to my email server but in email client I got: Unable to connect with STARTTLS: stream_socket_enable_crypto(): SSL operation failed with code 1. OpenSSL Error messages: error:14090086:SSL routines:ssl3_get_server_certificate:certificate verify failed. At the same time on my email server in /var/log/maillog I observed the following: …

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Postfix lookup in hosts file

In case you need to make Postfix look in your local /etc/hosts files before doing DNS lookup add following in main.cf file:

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Roundcube: SMTP server does not support authentication

When I try to send a letter from Roundcube I get the following error:

This can happen if Postfix doesn’t allow authentication from a localhost where Roundcube resides or if authentication scheme is wrong.

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Roundcube STARTTLS error SSL alert number 45

I’m working with a Postfix/Dovecot/Roundcube setup, aiming for a virtual user mail system that can send mail through the internet. Everything seems to work well; Dovecote shows no problems, I can telnet into all of my ports; however, whenever I try to send mail through Roundcube I get the error:

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How to Install and Configure GitLab on CentOS 7


Gitlab is an open source, powerful, robust, scalable, secure, as well as efficient software development and collaboration platform for all stages of the DevOps lifecycle. It allows you to plan your development process; code, and verify; package software, and release it with an in-built continuous delivery feature; automate configurations management, and monitor software performance. It …

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How To Install And Configure Mailman On Ubuntu

In this tutorial I will configure a virtual host with the hostname lists.example.com where I will install Mailman. lists.example.com is also the right part of the mailing list email addresses that will be configured in Mailman, i.e., mails to a mailing list will have to be sent to the address <listname>@lists.example.com. As your hostname will …

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Exchange Unable to relay (in reply to RCPT TO command)

If you use Microsoft Exchange as a mail relay for other servers, and on the server from which you send mail, you have an error Relay = exchangerelay.domain.com []: 25, delay = 5.1, delays = 0.04 / 0.01 / 0.05 / 5, dsn = 5.7.1, status = bounced (host exchangerelay.domain.com [] Said: 550 5.7.1 Unable …

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Change your Mail Transport Agent (MTA)

A Mail Transfer Agent (MTA) is a software that transfers electronic mail messages from one computer to another using a client server application architecture. An MTA is also called by a few other names such as – a Message Transfer Agent, Mail Relay, and Mail Transport Agent. Some of the popular MTAs in use are …

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Configure Postfix to use Gmail as a Mail Relay

Postfix is a free, open-source, actively maintained, and highly secure mail transfer agent. You can configure your system with Postfix to use Gmail as a mail relay. In order to do this follow the instruction below. Use sudo when needed or execute the commands below under “root” account.

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