Dovecot with imap, starttls, oauth2 proxy auth and sieve rules.

Uses SSMTP to send mails (for example if you have a redirect sieve rule).

create table if not exists virtual_domains (
	id serial primary key, 
	name text not null
);

create table if not exists virtual_users (
	id serial primary key, 
	domain_id integer not null references virtual_domains(id),
	email text not null,
	destination text not null
);


create table if not exists virtual_aliases (
	id serial primary key, 
	domain_id integer not null references virtual_domains(id),
	source text not null,
	destination text not null
);

Volumes

• /var/lib/vmail/mail

Environment Variables

HOSTNAME

Fully qualified name of the mail host.

GRANT_URL

OAuth2 url for token grants (password grant type).

INTROSPECTION_URL

OAuth2 url for token information.

USER_URL

OAuth2 url for getting available users, the username will be appended to the end.

CLIENT_ID

Id of the OAuth2 application.

CLIENT_SECRET

Secret of the OAuth2 application.

OAUTH_ADMIN_USER

User with which to perform user lookups (does not have to be an admin, but needs enough rights for that).

OAUTH_ADMIN_PASSWORD

Password for the OAUTH_ADMIN_USER.

SSMTP_MAIL_RELAY

Hostname and port for the used smtp relay (for example mail.example.com:587).

SSMTP_USER

User to authenticate agains the smtp relay.

SSMTP_PASSWORD

Password to authenticate agains the smtp relay.

SSMTP_AUTH_METHOD

• default: LOGIN

Which authentication mechanism to use for the smtp relay.

SSMTP_USE_STARTTLS

• default: yes

Whether to use starttls for the smtp relay.

ALLOWED_USERNAME_CHARS

• default: äöüabcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@

List of characters allowed in a username.

AUTH_MECHANISMS

• default: plain

Space seperated list of supported authentication mechanisms.

SSL_MIN_PROTOCOL

• default: TLSv1.2

Ssl minimum protocol version.

SSL_CIPHERLIST

• default: ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256

Colon seperated list of supported ciphers (!disables a cipher).

Go here for a list of ciphers.

IMAP_MAX_USER_CONNECTIONS

• default: 10

Maximum number of connections from the same user + ip.

Ports

• 143

Capabilities

• CHOWN
• DAC_OVERRIDE
• FOWNER
• NET_BIND_SERVICE
• SETGID
• SETUID
• SYS_CHROOT