AIOSMTPD(1) aiosmtpd AIOSMTPD(1)
NAME
aiosmtpd - asyncio based SMTP server
Provides an asynchronous, RFC 5321 compliant Simple Mail Transfer Proto-
col (SMTP) server that supports customizable extensions.
Author The aiosmtpd Developers
Date 2025-03-23
Copyright
2015-2022, The aiosmtpd Developers
Version
1.4.6
Manual section
1
SYNOPSIS
usage: aiosmtpd [-h] [-v] [-n] [-c CLASSPATH] [-s SIZE] [-u] [-d]
[-l [[HOST][:PORT]]] [--smtpscert CERTFILE]
[--smtpskey KEYFILE] [--tlscert CERTFILE] [--tlskey KEYFILE]
[--no-requiretls]
[CLASSARGS ...]
Options
CLASSARGS
Additional arguments passed to the handler CLASS.
-h, --help
show this help message and exit
-v, --version
show program's version number and exit
-n, --nosetuid
This program generally tries to setuid nobody, unless this flag
is set. The setuid call will fail if this program is not run as
root (in which case, use this flag).
-c <CLASSPATH>, --class <CLASSPATH>
Use the given class, as a Python dotted import path, as the han-
dler class for SMTP events. This class can process received mes-
sages and do other actions during the SMTP dialog. Uses
aiosmtpd.handlers.Debugging by default.
-s <SIZE>, --size <SIZE>
Restrict the total size of the incoming message to SIZE number of
bytes via the RFC 1870 SIZE extension. Defaults to 33,554,432
bytes.
-u, --smtputf8
Enable the SMTPUTF8 extension as defined in RFC 6531.
-d, --debug
Increase debugging output. Every -d increases debugging level by
one.
-l <[HOST][:PORT]>, --listen <[HOST][:PORT]>
Optional host and port to listen on. If the PORT part is not
given, then port 8025 is used. If only :PORT is given, then lo-
calhost is used for the hostname. If neither are given, local-
host:8025 is used.
--smtpscert <CERTFILE>
The certificate file for implementing SMTPS. If given, the para-
meter --smtpskey must also be specified.
--smtpskey <KEYFILE>
The key file for implementing SMTPS. If given, the parameter
--smtpscert must also be specified.
--tlscert <CERTFILE>
The certificate file for implementing STARTTLS. If given, the pa-
rameter --tlskey must also be specified.
--tlskey <KEYFILE>
The key file for implementing STARTTLS. If given, the parameter
--tlscert must also be specified.
--no-requiretls
If specified, disables require_starttls of the SMTP class. (By
default, require_starttls is True.) Has no effect if --tlscert
and --tlskey are not specified.
ENVIRONMENT
AIOSMTPD_CONTROLLER_TIMEOUT
How long the main thread will wait (in seconds) until the SMTP thread is ready.
Default: 1.0
AUTHOR
The aiosmtpd Developers
COPYRIGHT
2015-2022, The aiosmtpd Developers
1.4.6 2025-03-23 AIOSMTPD(1)
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