Domain verification
Configure sending domains to authenticate your emails. Lettermint requires domain verification before you can send emails.
Authentication Records
Lettermint uses three types DNS records for email authentication:
DKIM (DomainKeys Identified Mail): Adds cryptographic signatures to verify email authenticity.
DMARC (Domain-based Message Authentication): Defines policy for handling authentication failures.
Return-Path: A CNAME record that will be used as the envelope sender.
It is correct an SPF record is not discussed - it is managed via the Return-Path record.
Domain Verification
Step 1: Add Your Domain
- Add your domain in the Lettermint dashboard
- Enter your domain (we recommend a subdomain like mail.acme.com)
- Save!
Lettermint provides three DNS records to add to your domain (replace acme.com with the domain you added):
Return-Path Record
Add this CNAME record to your domain:
| Hostname | Type | Content |
|---|
lm-bounces.acme.com | CNAME | bounces.lmta.net |
If you’re using Cloudflare, ensure this CNAME record proxy status is set to “DNS only” instead of “Proxied”.
DKIM Record
Add the provided DKIM record (unique to your domain):
| Hostname | Type | Content |
|---|
lettermint._domainkey.acme.com | TXT | [value can be found in your dashboard] |
DMARC Record
We require every domain to setup a DMARC record. You are free to change the record, as long as it is valid.
The following record is the bare minimum:
| Hostname | Type | Content |
|---|
_dmarc.acme.com | TXT | v=DMARC1; p=reject; |
Troubleshooting
Verification failed
In order to check if your DNS record has been propagated, you can open a terminal and execute:
dig CNAME lm-bounces.acme.com
dig TXT lettermint._domainkey.acme.com
dig TXT _dmarc.acme.com
Common issues
- DNS records not yet propagated
- This can take up to 48 hours. Though usually we see that propagation happens within seconds to minutes.
- Incorrect record values
- Missing quotes around TXT record values
- Domain already appended to hostname
- Depending on the DNS provider you use it can be that they automatically append your domain after a record.
You can recognize this by noticing a record on e.g.
lm-bounces.acme.com.acme.com. If this is the case, you should add a single dot . after the hostname.
- Cloudflare proxy enabled
- If you’re using Cloudflare, ensure the CNAME record proxy status is set to “DNS only” instead of “Proxied”.