DNS records for email
MX records
The record that says which server receives your domain's mail. Change provider by changing this.
SPF
Which servers are allowed to send for your domain, the ten-lookup limit, and why forwarding breaks it.
DKIM
A cryptographic signature on every message, verified with a public key in DNS. Survives forwarding.
DMARC
Ties SPF and DKIM to the visible From address, sets a policy for forgeries, and sends you reports.
Protocols your mail client uses
IMAP
Keeps the mailbox on the server and every device in sync. Settings for ontechmail: port 993, TLS.
SMTP
How mail is submitted and relayed; ports 25, 465 and 587 explained. Settings for ontechmail: 465 or 587.
Setting up and choosing
- Email on your own domain, step by step: the order to publish records in so nothing is lost during a move.
- Email hosting explained: what a host does and what to check before choosing one.
- Self-hosted and on-premise email: when it is worth running the platform yourself.
- Email security for business: the controls that matter and which ones ontechmail provides.
- Data sovereignty: what a platform can and cannot promise about compliance.
Reference
Short definitions of every term used in these guides are in the glossary; product questions are answered in the FAQ; API examples are on the developers page.