Phase 11: Mail-client discovery — Self-Hosting Custom-Domain Email with Stalwart and Dokploy

11.1 IMAP and SMTP SRV records

Add:

Name: _imaps._tcp
Type: SRV
Priority: 0
Value: 1 993 mail.example.com.

Name: _submissions._tcp
Type: SRV
Priority: 0
Value: 1 465 mail.example.com.

Name: _submission._tcp
Type: SRV
Priority: 0
Value: 1 587 mail.example.com.

Some DNS providers separate the SRV fields:

Priority: 0
Weight: 1
Port: 993
Target: mail.example.com

Others place weight, port, and target into one Value field:

1 993 mail.example.com.

Verify:

dig +short SRV _imaps._tcp.example.com
dig +short SRV _submissions._tcp.example.com
dig +short SRV _submission._tcp.example.com

Expected:

0 1 993 mail.example.com.
0 1 465 mail.example.com.
0 1 587 mail.example.com.

Add DNS records:

autoconfig CNAME mail.example.com.
autodiscover CNAME mail.example.com.

Then create two additional Dokploy domains pointing to the same Stalwart service:

autoconfig.example.com
autodiscover.example.com

For each:

Service: stalwart-mail
Container port: 8080
HTTPS: Enabled
Certificate: Let's Encrypt

Verify Mozilla Autoconfig:

curl -i \
  "https://autoconfig.example.com/mail/config-v1.1.xml?emailaddress=user@example.com"

The XML should contain:

IMAP server: mail.example.com
IMAP port: 993
SMTP server: mail.example.com
SMTP port: 465