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Domain verification

Configure sending domains to authenticate your emails. Lettermint requires domain verification before you can send emails.

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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.

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Domain Verification

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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!

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Step 2: Configure DNS Records

Lettermint provides three DNS records to add to your domain (replace acme.com with the domain you added):

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Return-Path Record

Add this CNAME record to your domain:

HostnameTypeContent
lm-bounces.acme.comCNAMEbounces.lmta.net

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DKIM Record

Add the provided DKIM record (unique to your domain):

HostnameTypeContent
lettermint._domainkey.acme.comTXT[value can be found in your dashboard]

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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.

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Troubleshooting

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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

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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.