Fastmail + Porkbun

Set up Fastmail on Porkbun

The records Fastmail needs, written with the field names Porkbun uses (Host, Answer), in the order to add them.

  • 4 steps
  • 7 DNS records

Before you start

  1. Have your Fastmail account ready. Some values are unique to your account and come from the Fastmail Settings .
  2. Open DNS at Porkbun: Open Domain Management (ACCOUNT, then Domain Management). Click the DNS button under your domain, or Details and then the edit icon under DNS RECORDS.
  3. Keep both tabs open and add the records below one at a time.

Records to add

Copy each value with the button next to it. Rows marked “Copy from Fastmail Settings” are unique to your account.

MX records Where incoming email goes Type MX Host Leave empty Value in1-smtp.messagingengine.com Priority 10 TTL Default
MX records Where incoming email goes Type MX Host Leave empty Value in2-smtp.messagingengine.com Priority 20 TTL Default
SPF record Which servers may send as you Type TXT Host Leave empty Value v=spf1 include:spf.messagingengine.com ?all Priority n/a TTL Default
DKIM A signature on every message Type CNAME Host fm1._domainkey Value fm1.yourdomain.com.dkim.fmhosted.com Priority n/a TTL Default
DKIM A signature on every message Type CNAME Host fm2._domainkey Value fm2.yourdomain.com.dkim.fmhosted.com Priority n/a TTL Default
DKIM A signature on every message Type CNAME Host fm3._domainkey Value fm3.yourdomain.com.dkim.fmhosted.com Priority n/a TTL Default
DMARC record What to do with fakes · recommended Type TXT Host _dmarc Value v=DMARC1; p=none; Priority n/a TTL Default

Step by step in Porkbun

Point your MX records

MX records tell other mail servers where to deliver your email. How MX works

Type
MX
Host
Leave this field empty
Priority
10
Answer
in1-smtp.messagingengine.com
Type
MX
Host
Leave this field empty
Priority
20
Answer
in2-smtp.messagingengine.com

In Porkbun

  1. Choose MX as the Type.
  2. Leave Host blank, enter the mail server in Answer and the Priority your provider gives you. Leave TTL at its default.
  3. Click Add.
  4. Repeat for each MX record above.

Add the SPF record

SPF lists the services allowed to send email as you. How SPF works

Type
TXT
Host
Leave this field empty
Answer
v=spf1 include:spf.messagingengine.com ?all
  • This is the exact value from Fastmail's manual DNS guide, which ends in ?all (neutral).

In Porkbun

  1. Choose TXT as the Type.
  2. Leave Host blank for your bare domain (or enter the subdomain name), and paste the value in Answer.
  3. Click Add.

Set up DKIM

DKIM signs your mail so receivers can trust it. How DKIM works

Type
CNAME
Host
fm1._domainkey
Answer
fm1.yourdomain.com.dkim.fmhosted.com
Type
CNAME
Host
fm2._domainkey
Answer
fm2.yourdomain.com.dkim.fmhosted.com
Type
CNAME
Host
fm3._domainkey
Answer
fm3.yourdomain.com.dkim.fmhosted.com

In Porkbun

  1. Choose CNAME as the Type.
  2. Enter the Host (it can't be empty) and the target in Answer.
  3. Click Add.
  4. Repeat for each CNAME record above.

Add the DMARC record (recommended)

DMARC tells receivers what to do with mail that fakes your domain. How DMARC works

Type
TXT
Host
_dmarc
Answer
v=DMARC1; p=none;

In Porkbun

  1. Choose TXT as the Type.
  2. Leave Host blank for your bare domain (or enter the subdomain name), and paste the value in Answer.
  3. Click Add.

Check your setup

Once the records are saved, run a live check. We look up your domain in public DNS and tell you what is right, missing or wrong, with the fix in Porkbun’s words.

We only read public DNS records. Nothing is stored.

Common mistakes with Fastmail on Porkbun

Adding fewer than three DKIM records

Fastmail signs with three selectors (fm1, fm2, fm3). All three CNAMEs are required.

Adding a second SPF record

Only one record may start with v=spf1. Merge Fastmail's include into the existing one.

Porkbun: CNAME hosts must be unique

A CNAME's Host can't be empty and can't be shared with any other record on the domain.

Visit Fastmail Visit Porkbun

Fastmail on Porkbun: questions

Where do I add Fastmail DNS records in Porkbun?

Open Domain Management (ACCOUNT, then Domain Management). Click the DNS button under your domain, or Details and then the edit icon under DNS RECORDS. Add each record there, one at a time.

What goes in the Host field at Porkbun?

Leave it empty for records on your bare domain, such as MX and SPF. For the others, enter only the part before your domain, for example fm1._domainkey. Porkbun adds your domain automatically.

Do I need to delete my existing MX records at Porkbun?

Yes. Sending servers pick an MX record by its priority (lowest number first) and fall back to the others, so a leftover MX record can receive some or all of your mail. Keep only the Fastmail MX records and delete the rest.

Where do I get my Fastmail DKIM record?

Fastmail DKIM records are CNAME records whose value includes your domain, for example fm1.yourdomain.com.dkim.fmhosted.com. Copy the exact values for your domain from the table on this page.

Sources

Every value and step on this page comes from these official pages. Dashboards change, so if something doesn’t match what you see, tell us.

Fastmail on other hosts

Other email providers on Porkbun