maintained by MarvAmBass
FAQ - All you need to know about the marvambass Containers
This Dockerfile (available as marvambass/versatile-postfix) gives you a completly versatile postfix
mailserver.
It signs outgoing mails with DKIM by default. You can create one Domain with different users with their passwords. For multiple Domains you need to use multiple containers or create your own fork of this project.
This is not a POP3 or IMAP server, you will get incomming E-Mails in the Maildir format. Read it with less or link a IMAP Server to the volume.
View in Docker Registry marvambass/versatile-postfix
View in GitHub MarvAmBass/docker-versatile-postfix
ALIASES- optional, no default, example usage:
postmaster:root;john:root;j.doe:root DISABLE_DKIM- default: not set - if set to any value the DKIM Signing will be deactivated
DKIM_CANONICALIZATION- default:
simple- can be eitherrelaxedorsimple DKIM_SELECTOR- default:
mail, you can customize DKIM selector name
HIGH PRIORITY ENVIRONMENT VARIABLE
the following variable/s are only if you have some specific settings you need. They help you overwrite everything after the config was generated. If you can update your setting with the variables from above, it is strongly recommended to use them!
some characters might brake your configuration!
POSTFIX_RAW_CONFIG_<POSTFIX_SETTING_NAME_CASE_SENSETIVE>- set/edit all configurations in
/etc/postfix/main.cfusing thePOSTFIX_RAW_CONFIG_followed by the setting name (case sensetive)
- set/edit all configurations in
for example: to set mynetworks_style = subnet just add a environment variable POSTFIX_RAW_CONFIG_mynetworks_style=subnet
This Dockerfile is build to be as versatile as possible. Therefore the startup script takes care of all the important things.
You can easily create a new Mailserver for a domain with several users.
Keep in mind, this is a smtp server only. To read recievied mails you should link a folder inside the conatiner. Otherwise all mails will get lost after you delete your container.
To create a new postfix server for your domain you should use the following commands:
$ docker run -p 25:25 -v /maildirs:/var/mail \
-v /dkim:/etc/postfix/dkim/ \
-e 'ALIASES=postmaster:root;hostmaster:root;webmaster:root' \
marvambass/versatile-postfix \
yourdomain.com \
user:password \
user1:password \
user2:password \
userN:password
this creates a new smtp server which listens on port 25, stores mail beneath /mailsdirs.
The /dkim directory has to contain a DKIM-Key (see above) with the name dkim.key
It has serveral user accounts like user1 with password "password" and a mail address [email protected]
This Server uses DKIM by default. So we need our DKIM Keys.
If you don't have a DKIM Key, the Server will generate it on the first start.
Just be sure, that you make the directory /etc/postfix/dkim/ available and
install the logged public key to your DNS System
To generate those keys you'll need the opendkim tools
$ apt-get install opendkim-tools
This generates a new certificate for @example.com with selector -s mail. If you want to Test DKIM first, add -t argument which stands for test-mode.
$ opendkim-genkey -s mail -d example.com
Just put the file mail.private as dkim.key inside the dkim directory you'll later link into the container using -v.
The mail.txt should be imported into the DNS System. Add a new TXT-Record for mail._domainkey [selector._domainkey]. And add as value the String starting "v=DKIM1;..." from the mail.txt file.
Example:
$ cat mail.txt
mail._domainkey IN TXT ( "v=DKIM1; k=rsa; "
"p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDcUp8Q1sbxgnR2iL7w+TOHN1IR6PzAP3vmUoPfeN07NGfWo8Wzxyn+hqqnC+mbPOW4ZDoAiu5dvpPsCt1RQalwBw/iPlB/8ScTlPGRpsTLo4ruCDL+yVkw32/UhvCL8vbZxM/Q7ELjO6AqRRW/KuCvbd5gNRYGeyjWd+UQAfmBJQIDAQAB" ) ; ----- DKIM key mail for example.com
You need to put this line in your example.com DNS config zone:
mail._domainkey IN TXT "v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDcUp8Q1sbxgnR2iL7w+TOHN1IR6PzAP3vmUoPfeN07NGfWo8Wzxyn+hqqnC+mbPOW4ZDoAiu5dvpPsCt1RQalwBw/iPlB/8ScTlPGRpsTLo4ruCDL+yVkw32/UhvCL8vbZxM/Q7ELjO6AqRRW/KuCvbd5gNRYGeyjWd+UQAfmBJQIDAQAB"
Thats all you need for DKIM
Check DNS config:
$ host -t TXT mail._domainkey.example.com
mail._domainkey.example.com descriptive text "v=DKIM1\; k=rsa\; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDcUp8Q1sbxgnR2iL7w+TOHN1IR6PzAP3vmUoPfeN07NGfWo8Wzxyn+hqqnC+mbPOW4ZDoAiu5dvpPsCt1RQalwBw/iPlB/8ScTlPGRpsTLo4ruCDL+yVkw32/UhvCL8vbZxM/Q7ELjO6AqRRW/KuCvbd5gNRYGeyjWd+UQAfmBJQIDAQAB"
$ mailx -r "[email protected]" -s "Test Mail Subject" [email protected] < /etc/hosts
$ echo -ne '\0user\0password' | openssl enc -base64
AHVzZXIAcGFzc3dvcmQ=
$ telnet 127.0.0.1 25
Trying 192.168.4.55...
Connected to yourdomain.com.
Escape character is '^]'.
220 yourdomain.com ESMTP
ehlo test
250-yourdomain.com
250-PIPELINING
250-SIZE 10240000
250-VRFY
250-ETRN
250-STARTTLS
250-AUTH LOGIN PLAIN
250 8BITMIME
auth plain AHVzZXIAcGFzc3dvcmQ=
235 Authentication successful
mail from: [email protected]
250 2.1.0 Ok
rcpt to: [email protected]
250 2.1.5 Ok
data
354 End data with <CR><LF>.<CR><LF>
Hi there
this is just a basic test message
.
250 2.0.0 Ok: queued as 2E7FB27F
quit
221 Bye
Connection closed by foreign host.