How to Change the Outgoing Mail IP Address in Plesk on Linux

When the IP address your server sends email from ends up on a blacklist, you may want to send your email from another IP address. In Plesk, this setting is available on Linux servers with the Postfix mail server.

First find and stop the source of the spam; otherwise the new IP address will soon be blacklisted too.

Before you start

• Postfix must be the mail server (the default for Plesk on Linux).
• The IP address you want to send from must be configured on the server and added to Plesk. After adding the extra IP to the server, reread it in Plesk with Reread IP on Tools & Settings > IP Addresses.
• We recommend setting the reverse record (rDNS) of the new IP address to your server's hostname; you can edit it in your client area.

Setting

On Tools & Settings > Mail Server Settings (under Mail), you can choose one of three options for outgoing mail:

• Send from domain IP addresses: the default. Mail from each domain is sent from that domain's IP address; the Plesk server hostname is used in the SMTP greeting. Works best if the server has a single IP address.
• Send from domain IP addresses and use domain names in SMTP greeting: the same, but the SMTP greeting contains the name of the sending domain. If several domains share an IP address, mail may be marked as spam; on servers with more than 100 domains it significantly increases the load. Works best when every domain has its own IP address.
• Send from the specified IP address: all mail is sent from the IPv4 and IPv6 addresses you choose. This is the option to use when the server's mail IP address has been blacklisted. If you select None, outgoing mail is not sent.

When you save your choice, Plesk changes the mail server configuration by itself.

The information in this guide is taken from official documentation: Plesk: Configuring Server-Wide Mail Settings.