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MailPlus License Pack

Synology MailPlus license packs are designed for adding active email accounts on Synology MailPlus. By default, 5 licenses are installed on a MailPlus supported Synology NAS, and extra licenses can be purchased for additional email accounts according to business needs.

5 Email Accounts
20 Email Accounts

Licensing Plan

Synology MailPlus comes with 5 free email accounts and allows you to add more accounts with additional purchased licenses. We provide two kinds of license packs to suit your needs: 5 or 20 units of email accounts1, both with perpetual validity2. The included licenses can only be applied to one Synology NAS, and cannot be migrated3 to another Synology NAS once activated.
In addition, email aliases are not considered as email accounts and therefore do not require any license for use.

To know the recommended number of active email accounts for each MailPlus supported model, please visit the product overview page, and go to the model's Specifications page for information.


  1. Once the purchased license key is applied, all its included licenses will be activated at the same time.
  2. The activated licenses remain permanently valid unless the registered Synology NAS is down.
  3. For any special need for license migration (e.g. RMA products), please contact Synology Support team for further assistance.

High-availability Architecture

No additional fee will be charged for the high-availability support in MailPlus, and one cluster includes 10 free mail accounts by default. To have more licensed email accounts for use, you need to apply purchased license keys from Synology. For example, if you want to enable 25 email accounts in the high-availability cluster, then 15 additional licenses are needed.

MailPlus Web Client and Mobile App

MailPlus web client and its mobile app (available for Android and iOS) do not charge fees for use, and they will be updated regularly for free with MailPlus Server.

License Activation and Account Management

To apply purchased license keys, you will have to log in to the Synology NAS as the administrator. Then, open MailPlus Server and go to License to apply the keys (Internet connection required). One license key can only be applied to one MailPlus supported Synology NAS.
To activate or deactivate email accounts, go to Account for management.

To check all your activated licenses, please log in to your Synology Account.

MailPlus Features

Learn more about MailPlus features here.

Applied Models

MailPlus will be available on the following models:

Model Recommended MailPlus Client Number Maximum Server Performance
FS3017 1800 4,129,000
FS2017 900 3,604,000
FS1018 200 1,572,000 (Btrfs) / 1,524,000 (EXT4)
RS18017xs+ 600 (Btrfs) / 700 (EXT4) 3,088,000 (Btrfs) / 3,009,000 (EXT4)
RS4017xs+ 800 (Btrfs) / 900 (EXT4) 3,618,000 (Btrfs) / 2,738,000 (EXT4)
RS3618xs 400 (Btrfs) / 450 (EXT4) 2,621,000 (Btrfs) / 2,412,000 (EXT4)
RS3617xs+ 600 (Btrfs) / 700 (EXT4) 3,088,000 (Btrfs) / 3,009,000 (EXT4)
RS3617RPxs 400 (Btrfs) / 450 (EXT4) 2,621,000 (Btrfs) / 2,412,000 (EXT4)
RS2818RP+ 100 (Btrfs) / 100 (EXT4) 940,000 (Btrfs) / 1,016,000 (EXT4)
RS2418+/RS2418RP+ 100 (Btrfs) / 100 (EXT4) 940,000 (Btrfs) / 1,016,000 (EXT4)
RS818+/RS818RP+ 90 (Btrfs) / 100 (EXT4) 712,000 (Btrfs) / 844,000 (EXT4)
RC18015xs+ 500 (Btrfs) / 500 (EXT4) 2,166,000 (Btrfs) / 2,418,000 (EXT4)
DS3617xs 400 (Btrfs) / 400 (EXT4) 3,283,000 (Btrfs) / 1,992,000 (EXT4)
DS3018xs 200 (Btrfs) / 200 (EXT4) 1,616,000 (Btrfs) / 1,782,000 (EXT4)
DS2415+ 90 (Btrfs) / 100 (EXT4) 825,000 (Btrfs) / 884,000 (EXT4)
DS1817+ 90(btrfs)/100(ext4) 825,000
DS1618+ 100 (Btrfs) / 100 (EXT4) 1,055,000 (Btrfs) /1,171,000 (EXT4)
DS1517+ 90(btrfs)/100(ext4) 712,000
DS918+ 90 (Btrfs) / 90 (ext4) 840,000 (Btrfs) / 1,014,000 (ext4)
DS718+ 90 (Btrfs) / 90 (ext4) 831,000 (Btrfs) / 966,000 (ext4)
DS418play 45 (Btrfs) / 45 (ext4) 181,000 (Btrfs) / 194,000 (ext4)
DS218+ 45 (Btrfs) / 45 (ext4) 181,000 (Btrfs) / 194,000 (ext4)