dma (Dragonfly Mail Agent) is a tiny Mail Transport Agent (MTA). It is able to accept mails and deliver it to local or remote destinations; however, if you want to send and receive mails with your domain name, then you will need a full-featured mail server.
dma has two main configuration files:
/etc/dma/dma.conf contains main setup directives and
/etc/dma/auth.conf is necessary for authentication on SMTP servers. dma provides sane defaults so you may be able to use it without special configuration for local mail delivery.
If you want to route mail through external SMTP server you must set
SMARTHOST address (also known as relay host) in
Also do not forget to set authentication credentials in
/etc/dma/auth.conf in the following format:
To have dma actually use the credentials file, set
To change default port set
PORT directive (
25 is default):
# accept mail from external MTAs (STARTTLS is also an option) PORT 25 # accept mail from MUAs with TLS PORT 465 # accept mail from MUAs (STARTTLS is also an option) PORT 587
SECURETRANSFER directive enables encryption during mail transfers. Depending on your needs uncomment
STARTTLS to enable STARTTLS support and activate
OPPORTUNISTIC_TLS to permit unencrypted fallback in case of error.
For whatever reason you may want to perform plain text SMTP authentication. In such case uncomment
SECURE directive and change it to
If you want to substitute original From: field in envelope you can use
# send mails as user foo (hostname will be derived with gethostbyname() or set to MAILNAME directive) MASQUERADE foo@ # send mails from host bar (username will be substituted) MASQUERADE bar # send mail as user foo from host bar MASQUERADE foo@bar
To send test mail execute the following from command line:
$ mail -s "Just a dma test" email@example.com This is just a small test message <Ctrl+D>
journalctl -r as root to see if all went good. Also you can check dma queue with:
$ dma -bp
/var/spool/dma directory also holds undelivered/unprocessed mails.
Send mails through Google's SMTP servers
To do that login into your Google Account, choose Security entry on the left panel and click on App Passwords in Signing in to Google panel. If you do not see this item please consult corresponding thread on Google.
Click on Select app and choose desired application (usual called as Mail). Then click on Select device and choose the device, but it is better to add custom device and call it appropriately for easy future management. Then click on Generate and write down your App Password (16-character code in the yellow bar).
SMARTHOST smtp.gmail.com PORT 587 AUTHPATH /etc/dma/auth.conf SECURETRANSFER STARTTLS MASQUERADE firstname.lastname@example.org
The MASQUERADE line ensures that mails sent by DMA appear to come from the specified user. Google will reject emails that do not come from the correct Google account.