Values in **bold** are the default values. If an option doesn't work as documented here, check if you are running the latest image. The current `master` branch corresponds to the image `mailserver/docker-mailserver:edge`.
- empty => uses the `hostname` command to get the mail server's canonical hostname.
- => Specify a fully-qualified domainname to serve mail for. This is used for many of the config features so if you can't set your hostname (e.g. you're in a container platform that doesn't let you) specify it in this environment variable.
- 1 => consolidate all states into a single directory (`/var/mail-state`) to allow persistence using docker volumes.
##### PERMIT_DOCKER
Set different options for mynetworks option (can be overwrite in postfix-main.cf) **WARNING**: Adding the docker network's gateway to the list of trusted hosts, e.g. using the `network` or `connected-networks` option, can create an [**open relay**](https://en.wikipedia.org/wiki/Open_mail_relay), for instance if IPv6 is enabled on the host machine but not in Docker.
- **empty** => localhost only.
- host => Add docker host (ipv4 only).
- network => Add the docker default bridge network (172.16.0.0/12); **WARNING**: `docker-compose` might use others (e.g. 192.168.0.0/16) use `PERMIT_DOCKER=connected-networks` in this case.
- connected-networks => Add all connected docker networks (ipv4 only).
Note: you probably want to [set `POSTFIX_INET_PROTOCOLS=ipv4`](#postfix_inet_protocols) to make it work fine with Docker.
- Requires: `SSL_CERT_PATH` and `SSL_KEY_PATH` ENV vars to be set to the location of the files within the container.
- Optional: `SSL_ALT_CERT_PATH` and `SSL_ALT_KEY_PATH` allow providing a 2nd certificate as a fallback for dual (aka hybrid) certificate support. Useful for ECDSA with an RSA fallback. Presently only `manual` mode supports this feature.
- modern => Enables TLSv1.2 and modern ciphers only. (default)
- intermediate => Enables TLSv1, TLSv1.1 and TLSv1.2 and broad compatibility ciphers.
##### SPOOF_PROTECTION
Configures the handling of creating mails with forged sender addresses.
- **empty** => Mail address spoofing allowed. Any logged in user may create email messages with a forged sender address. See also [Wikipedia](https://en.wikipedia.org/wiki/Email_spoofing)(not recommended, but default for backwards compatibility reasons)
- 1 => (recommended) Mail spoofing denied. Each user may only send with his own or his alias addresses. Addresses with [extension delimiters](http://www.postfix.org/postconf.5.html#recipient_delimiter) are not able to send messages.
##### ENABLE_SRS
Enables the Sender Rewriting Scheme. SRS is needed if your mail server acts as forwarder. See [postsrsd](https://github.com/roehling/postsrsd/blob/master/README.md#sender-rewriting-scheme-crash-course) for further explanation.
- **0** => Disabled
- 1 => Enabled
##### NETWORK_INTERFACE
In case your network interface differs from `eth0`, e.g. when you are using HostNetworking in Kubernetes, you can set this to whatever interface you want. This interface will then be used.
- **empty** => `eth0`
##### VIRUSMAILS_DELETE_DELAY
Set how many days a virusmail will stay on the server before being deleted
- **empty** => 7 days
##### ENABLE_POSTFIX_VIRTUAL_TRANSPORT
This Option is activating the Usage of POSTFIX_DAGENT to specify a ltmp client different from default dovecot socket.
- **empty** => disabled
- 1 => enabled
##### POSTFIX_DAGENT
Enabled by ENABLE_POSTFIX_VIRTUAL_TRANSPORT. Specify the final delivery of postfix
- **empty**: fail
-`lmtp:unix:private/dovecot-lmtp` (use socket)
-`lmtps:inet:<host>:<port>` (secure lmtp with starttls, take a look at <https://sys4.de/en/blog/2014/11/17/sicheres-lmtp-mit-starttls-in-dovecot/>)
-`lmtp:<kopano-host>:2003` (use kopano as mailstore)
- etc.
##### POSTFIX\_MAILBOX\_SIZE\_LIMIT
Set the mailbox size limit for all users. If set to zero, the size will be unlimited (default).
Set the message size limit for all users. If set to zero, the size will be unlimited (not recommended!)
- **empty** => 10240000 (~10 MB)
##### ENABLE_MANAGESIEVE
- **empty** => Managesieve service disabled
- 1 => Enables Managesieve on port 4190
##### OVERRIDE_HOSTNAME
- **empty** => uses the `hostname` command to get the mail server's canonical hostname
- => Specify a fully-qualified domainname to serve mail for. This is used for many of the config features so if you can't set your hostname (e.g. you're in a container platform that doesn't let you) specify it in this environment variable.
- **enforce** => Allow other tests to complete. Reject attempts to deliver mail with a 550 SMTP reply, and log the helo/sender/recipient information. Repeat this test the next time the client connects.
- drop => Drop the connection immediately with a 521 SMTP reply. Repeat this test the next time the client connects.
- ignore => Ignore the failure of this test. Allow other tests to complete. Repeat this test the next time the client connects. This option is useful for testing and collecting statistics without blocking mail.
##### DOVECOT_MAILBOX_FORMAT
- **maildir** => uses very common Maildir format, one file contains one message
- sdbox => (experimental) uses Dovecot high-performance mailbox format, one file contains one message
- mdbox ==> (experimental) uses Dovecot high-performance mailbox format, multiple messages per file and multiple files per box
This option has been added in November 2019. Using other format than Maildir is considered as experimental in docker-mailserver and should only be used for testing purpose. For more details, please refer to [Dovecot Documentation](https://wiki2.dovecot.org/MailboxFormat).
##### POSTFIX_INET_PROTOCOLS
- **all** => All possible protocols.
- ipv4 => Use only IPv4 traffic. Most likely you want this behind Docker.
- ipv6 => Use only IPv6 traffic.
Note: More details in <http://www.postfix.org/postconf.5.html#inet_protocols>
#### Reports
##### PFLOGSUMM_TRIGGER
Enables regular pflogsumm mail reports.
- **not set** => No report
- daily_cron => Daily report for the previous day
- logrotate => Full report based on the mail log when it is rotated
This is a new option. The old REPORT options are still supported for backwards compatibility.
If this is not set and reports are enabled with the old options, logrotate will be used.
##### PFLOGSUMM_RECIPIENT
Recipient address for pflogsumm reports.
- **not set** => Use REPORT_RECIPIENT or POSTMASTER_ADDRESS
- => Specify the recipient address(es)
##### PFLOGSUMM_SENDER
From address for pflogsumm reports.
- **not set** => Use REPORT_SENDER or POSTMASTER_ADDRESS
- => Specify the sender address
##### LOGWATCH_INTERVAL
Interval for logwatch report.
- **none** => No report is generated
- daily => Send a daily report
- weekly => Send a report every week
##### LOGWATCH_RECIPIENT
Recipient address for logwatch reports if they are enabled.
- **not set** => Use REPORT_RECIPIENT or POSTMASTER_ADDRESS
- => Specify the recipient address(es)
##### REPORT_RECIPIENT (deprecated)
Enables a report being sent (created by pflogsumm) on a regular basis.
- **0** => Report emails are disabled unless enabled by other options
- 1 => Using POSTMASTER_ADDRESS as the recipient
- => Specify the recipient address
##### REPORT_SENDER (deprecated)
Change the sending address for mail report
- **empty** => mailserver-report@hostname
- => Specify the report sender (From) address
##### REPORT_INTERVAL (deprecated)
Changes the interval in which logs are rotated and a report is being sent (deprecated).
- **daily** => Send a daily report
- weekly => Send a report every week
- monthly => Send a report every month
Note: This variable used to control logrotate inside the container and sent the pflogsumm report when the logs were rotated.
It is still supported for backwards compatibility, but the new option LOGROTATE_INTERVAL has been added that only rotates
the logs.
##### LOGROTATE_INTERVAL
Defines the interval in which the mail log is being rotated.
- **daily** => Rotate daily.
- weekly => Rotate weekly.
- monthly => Rotate monthly.
Note that only the log inside the container is affected.
The full log output is still available via `docker logs mail` (or your respective container name).
If you want to control logrotation for the docker generated logfile see: [Docker Logging Drivers](https://docs.docker.com/config/containers/logging/configure/).
Also note that by default the logs are lost when the container is recycled. To keep the logs, mount a volume.
Finally the logrotate interval **may** affect the period for generated reports. That is the case when the reports are triggered by log rotation.
Note: this SpamAssassin setting needs `ENABLE_SPAMASSASSIN=1`. By default, the mailserver is configured to quarantine spam emails. If emails are quarantined, they are compressed and stored in a location dependent on the ONE_DIR setting above. If `ONE_DIR=1` the location is /var/mail-state/lib-amavis/virusmails/. If `ONE_DIR=0` it is /var/lib/amavis/virusmails/. These paths are inside the docker container. To inhibit this behaviour and deliver spam emails, set this to a very high value e.g. 100.0.
Note: this SpamAssassin setting needs `ENABLE_SPAMASSASSIN=1`. Add the SpamAssassin score to the subject line by inserting the keyword \_SCORE\_: **\*\*\*SPAM(\_SCORE\_)\*\*\***.
**0** => `fetchmail` runs with a single config file `/etc/fetchmailrc`
**1** => `/etc/fetchmailrc` is split per poll entry. For every poll entry a seperate fetchmail instance is started to allow having multiple imap idle configurations defined.
Note: The defaults of your fetchmailrc file need to be at the top of the file. Otherwise it won't be added correctly to all separate `fetchmail` instances.
- A second container for the ldap service is necessary (e.g. [docker-openldap](https://github.com/osixia/docker-openldap))
- For preparing the ldap server to use in combination with this container [this](http://acidx.net/wordpress/2014/06/installing-a-mailserver-with-postfix-dovecot-sasl-ldap-roundcube/) article may be helpful
The following variables overwrite the default values for ```/etc/dovecot/dovecot-ldap.conf.ext```.
##### DOVECOT_BASE
- **empty** => same as `LDAP_SEARCH_BASE`
- => Tell Dovecot to search only below this base entry. (e.g. `ou=people,dc=domain,dc=com`)
##### DOVECOT_DEFAULT_PASS_SCHEME
- **empty** => `SSHA`
- => Select one crypt scheme for password hashing from this list of [password schemes](https://doc.dovecot.org/configuration_manual/authentication/password_schemes/).
##### DOVECOT_DN
- **empty** => same as `LDAP_BIND_DN`
- => Bind dn for LDAP connection. (e.g. `cn=admin,dc=domain,dc=com`)
##### DOVECOT_DNPASS
- **empty** => same as `LDAP_BIND_PW`
- => Password for LDAP dn sepecifified in `DOVECOT_DN`.
- **envelope_sender** => Rewrite only envelope sender address
- header_sender => Rewrite only header sender (not recommended)
- envelope_sender,header_sender => Rewrite both senders
##### SRS_EXCLUDE_DOMAINS
- **empty** => Envelope sender will be rewritten for all domains
- provide comma separated list of domains to exclude from rewriting
##### SRS_SECRET
- **empty** => generated when the container is started for the first time
- provide a secret to use in base64
- you may specify multiple keys, comma separated. the first one is used for signing and the remaining will be used for verification. this is how you rotate and expire keys
- if you have a cluster/swarm make sure the same keys are on all nodes
- example command to generate a key: `dd if=/dev/urandom bs=24 count=1 2>/dev/null | base64`
##### SRS_DOMAINNAME
- **empty** => Derived from OVERRIDE_HOSTNAME, DOMAINNAME, or the container's hostname
- Set this if auto-detection fails, isn't what you want, or you wish to have a separate container handle DSNs
#### Default Relay Host
##### DEFAULT_RELAY_HOST
- **empty** => don't set default relayhost setting in main.cf
- default host and port to relay all mail through.
Format: `[example.com]:587` (don't forget the brackets if you need this to
be compatible with `$RELAY_USER` and `$RELAY_PASSWORD`, explained below).
#### Multi-domain Relay Hosts
##### RELAY_HOST
- **empty** => don't configure relay host
- default host to relay mail through
##### RELAY_PORT
- **empty** => 25
- default port to relay mail through
##### RELAY_USER
- **empty** => no default
- default relay username (if no specific entry exists in postfix-sasl-password.cf)
