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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

  1. Add your domain in the Lettermint dashboard
  2. Enter your domain (we recommend a subdomain like mail.acme.com)
  3. Save!

Step 2: Configure DNS Records

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:
HostnameTypeContent
lm-bounces.acme.comCNAMEbounces.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):
HostnameTypeContent
lettermint._domainkey.acme.comTXT[value can be found in your dashboard]
If you want more information on DKIM records, check out this guide.

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:
HostnameTypeContent
_dmarc.acme.comTXTv=DMARC1; p=reject;
If you want more information on DMARC records, check out this guide.

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”.
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