Email

#Installation and modes

The mail server only runs on a server installation (native). By default the installer sets up Postfix, Dovecot (2.3 or 2.4), OpenDKIM and Roundcube; pass --without-mail if you do not want mail. See Installation for details.

On container installations, use an external mail provider; see Docker and Railway.

Add-ons (Rspamd, ClamAV, SnappyMail, imapsync, Radicale, mlmmj, SMTP relay modules) are installed separately from Server Admin → Components. Which email tools users see is switched on or off per package; see Accounts and packages.

#Mailboxes and quotas

In the user panel, Email → Email Accounts is where you create mailboxes, change their password and quota, and delete them (optionally together with their mail).

• Quota: set in MB. It cannot exceed the package's maximum mailbox quota; if left empty, the package maximum applies.
• Count limit: as many mailboxes as the package allows.
• Suspension: login and incoming mail can be suspended separately; suspending login also disconnects open IMAP/POP3 sessions.

Mail is stored under /var/vmail/<domain>/<user>/Maildir. Mailbox Maintenance repairs permissions and recalculates quota usage; converting between Maildir and mdbox is a Pro feature started by the server administrator.

#Forwarders, autoresponders and filters

• Forwarders: deliver mail for an address to one or more destinations; an address cannot forward to itself.
• Autoresponders: per mailbox, with a subject, a message and an optional start and end date (vacation reply).
• Email Filters: per-mailbox Sieve rules with a rule builder, a raw Sieve editor and a test against a sample message. Global Email Filters apply to every mailbox of the account.
• Server-wide Email Filters: in Server Admin, for the server administrator only; they run before the rules of every mailbox.

#Spam and virus protection

Spam protection is provided by the Rspamd component; while it is not installed, mail flows unfiltered.

The server administrator manages defaults, greylisting, learning and statistics in Server Admin → Spam Protection. Users edit domain and mailbox settings and allow and block lists on the Spam Filters page. Moving a message to the Junk folder teaches Rspamd that it is spam. Country and sender-domain filters and sender verification are Pro features.

The Virus Scanner (ClamAV component) scans incoming mail through Rspamd and can also scan account home directories; for infected mail, reject or quarantine is chosen per domain.

#SPF, DKIM and DMARC

The Email → Email Deliverability page checks the SPF, DKIM, DMARC, MX and reverse DNS (PTR) records of each domain against live DNS. If the DNS zone is managed by bipanel, missing records are added in one click:

If the zone is hosted elsewhere, the page lists the records you need; add them at your domain provider. The PTR record is set at your server provider. For DNS itself, see DNS.

#Webmail and mail clients

Roundcube ships with the installation at /webmail; SnappyMail runs at /snappymail once installed as a component. In Server Admin → Webmail you choose which apps are enabled and which one is the default. The Webmail item in the user menu opens the app directly when only one is enabled; otherwise it shows the Webmail Apps page. With GnuPG Keys, messages can be signed and encrypted in Roundcube.

The Connect Devices page provides server settings, an Apple profile and Thunderbird/Outlook autoconfiguration. Ports: IMAP 993 (143 with STARTTLS), POP3 995, SMTP 465 and 587. In Server Admin → Mail Client Setup you pick the host name clients use and manage SRV/autoconfig DNS records and certificates; the Dovecot (IMAP/POP3) page shows per-domain certificates (SNI).

#Calendars and contacts

CalDAV/CardDAV is a Pro feature: it runs on the Radicale component, users sign in with their mailbox password, and it is enabled per mailbox.

#Mailing lists and archive

• Mailing Lists (Pro): based on mlmmj; lists per domain, members (CSV import/export), moderation and archive.
• Email Archive (Pro): a copy of incoming and outgoing mail is kept with a per-domain retention period and can be searched and downloaded.

#Migrating from another server

The Email Migration page pulls mail from another server over IMAP, one mailbox at a time or in bulk from a CSV list, and verifies message counts per folder. It uses imapsync when installed, otherwise Dovecot (changeable in Server Admin → Email Migrations; by default 2 migrations run in parallel). Import Addresses creates mailboxes and forwarders in bulk from a CSV file. To move whole accounts from another control panel, see Backups and migration.

#Routing, relay and sending limits

On the Email Routing page you choose a mode for each domain and set the catch-all address:

In Server Admin:

• Sending Limits: hourly limits at server, package, account and domain level, counted per recipient over the last 60 minutes. The server default is unlimited.
• SMTP Relay: sends outgoing mail through a provider. A separate relay per sender domain (Domain Relays) is a Pro feature.
• Mail Server: Postfix, Dovecot and OpenDKIM status plus the mail queue (search, retry, hold and release, delete).
• Track Delivery and Mail Statistics: delivery records from the mail log, a sender report and high bounce rate alerts. Users follow their own domains on the matching user panel pages.

#Hardening

• Sender Identity Protection (off by default): when enabled, a mailbox can only send as its own addresses and an account's scripts only as the account's domains. Users manage allowed addresses on the Sender Addresses page.
• SMTP Restrictions: only the mail server and root may connect to ports 25, 465 and 587 on external servers; PHP scripts have to use the local mail server, so sending limits and DKIM signing cannot be bypassed.

For other tools, see Security tools; for edition differences, see Pricing. The Community edition is limited to 3 hosting accounts.