Simplest and Smallest Email Forward Service based on Docker.
View on Github - https://github.com/zixia/docker-simple-mail-forwarder
What is SMF? (Simple Mail Forwarder)
If you had a domain name and only wanted to have one(or a few) email address from this domain, but you want to forward all the emails to another email account. SMF is exactly what you need. (with Docker)
This docker was built for ultimate simplicity because of this reason. I owned many domains and needed email addresses of them(for fun/work), and I hated to config email server. Some DNS providers provide free email forwarding service for their own domain, some do not. And almose all email forwarding service is NOT free. So I decided to make it myself(thanks docker).
- DuoCircle Email Forwarding From $59.95/year
- Cloud Mail In From $9/month. And it is not for human.
- MailGun professional service. Free plan includes 10,000 emails/month. but can result in your domain being treated as spam
I was willing to pay $10/year, but the cheapest plan I could find was $9 per month. Having a $10 USD machine with unlimited mail&domains per month is an amazing idea! And of couse you could also put other dockers on this same machine. :-D
Quick Start (TL;DR)
SMF_CONFIG and run:
$ export SMF_CONFIGfirstname.lastname@example.org:email@example.com:test' $ docker run -e SMF_CONFIG=$SMF_CONFIG -p 25:25 zixia/simple-mail-forwarder
Don't forget to modify the DNS MX record of your domain. (in this example, it's testo.com)
This will forward all emails received by firstname.lastname@example.org to email@example.com.
See? There is nothing easier.
How to run:
$ docker run zixia/simple-mail-forwarder test >> exec bats test 1..20 ok 1 confirm hostname pretend to work. ok 2 confirm hwclock pretend to work. ok 3 service postfix could start/stop right. ok 4 SMF_CONFIG exist ok 5 SMF_DOMAIN exist ok 6 virtual maping source is set ok 7 virtual maping data is set ok 8 virtual maping db is set ok 9 system hostname FQDN resolvable ok 10 postfix myhostname FQDN & resolvable ok 11 check other hostname setting ok 12 confirm postfix is running ok 13 confirm port 25 is open ok 14 crond is running ok 15 ESMTP STATTLS supported ok 16 ESMTP AUTH supported ok 17 ESMTP STARTTLS supported ok 18 create user firstname.lastname@example.org by password test ok 19 ESMTP AUTH by email@example.com/test ok 20 ESMTP TLS AUTH by firstname.lastname@example.org/test
You are all set! :-]
Environment Variable and Default Values
SMF_CONFIG: MUST be defined. no default setting. (set me! I'm the only parameter~)
Here's how to config the only environment parameter of SMF Docker:
Forward all emails received by email@example.com to firstname.lastname@example.org:
$ export SMF_CONFIGemail@example.com:firstname.lastname@example.org'
You could get the ESMTP AUTH password for you on your docker log. It's randomly generated if you do not provide one.
Add ESMTP AUTH password:
$ export SMF_CONFIGemail@example.com:firstname.lastname@example.org:ThisIsPassword'
Password will be printed on the docker log.
Add as many email accounts as you want, with or without password. Seperated by semicolon or a new line:
$ export SMF_CONFIGemail@example.com:firstname.lastname@example.org:ThisIsPassword;email@example.com:firstname.lastname@example.org:AnotherPassword'
Tips: if you only provide the first password and leave the rest blank, then the passwords for all the rest accounts will be the same as the last password value you set. This is by design.
Build from source.
$ ./script/build.sh latest
Run a self-test for SMF docker.
$ ./script/run.sh latest test
Get a shell inside SMF docker.
$ ./script/devshell.sh latest
$ telnet 127.0.0.1 25 > 220 testo.com ESMTP ehlo test.com > 250-testo.com > 250-STARTTLS > 250-AUTH PLAIN LOGIN auth plain > 334 dGVzdGlAdGVzdG8uY29tAHRlc3RpQHRlc3RvLmNvbQB0ZXN0 > 235 2.7.0 Authentication successful quit > 221 2.0.0 Bye > Connection closed by foreign host
P.S. The magic string
dGVzdGlAdGVzdG8uY29tAHRlc3RpQHRlc3RvLmNvbQB0ZXN0 stands for
email@example.com\firstname.lastname@example.org\0test in base64 encoding, required by AUTH PLAIN.
Useful article about SMTP Authentication: http://www.fehcom.de/qmail/smtpauth.html
Github Issue - https://github.com/zixia/docker-simple-mail-forwarder/issues
- close issue #1
- increace message size limit from 10MB to 40MB
- switch FROM image from alpine to sillelien/base-alpine
- NOT to use OpenRC(very buggy run inside docker container) any more!
- better ESMTP TLS AUTH test script
- docker image size: 10MB
v0.3.0 <- Don't use me, I'm BUGGY
- CI(continuous integration) supported by use CircleCI
- CD(continuous delivery) supported by use Tutum Button
- write better tests
- tune OpenRC inside alpine linux
- full description README
- docker image size: 7MB
v0.2.0 <- Don't use me, I'm BUGGY
- supported specify user password
- supported ESMTP TLS
- docker image size: 7MB
- basic forward function
- docker image size: 6MB
- A Cloud Service that could host docker is required.
- A Docker management platform is recommanded.
- Docker is required.
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Copyright & License
- Code & Documentation 2015© zixia
- Code released under the Apache 2.0 license
- Docs released under Creative Commons