Postmark’s SPF include goes on a subdomain, not your root record.
Postmark’s recommended setup is a Return-Path CNAME, not an include on your root. Postmark says adding include:spf.mtasv.net to your root record “will do nothing for you”, because its SPF check runs on the Return-Path domain; use the CNAME instead. Measured on 6 Nov 2026, the include costs 1 of your 10 SPF lookups, leaving 9 for everything else.
- Include
- spf.mtasv.net
- Vendor’s record
- v=spf1 a mx include:spf.mtasv.net ~all
- Where it goes
- A subdomain the service gives you
- Needed on your root?
- Only with a custom return-path/MAIL FROM
- Lookups (measured)
- 1 of 10
- Ranges published
- 4 ip4 · 0 ip6
- Category
- Transactional email
What include:spf.mtasv.net expands to live, 6 Nov 2026
v=spf1 ip4:50.31.156.96/27 ip4:104.245.209.192/26 ip4:50.31.205.0/24 ip4:147.160.158.0/24 -all
Counted as RFC 7208 §4.6.4 does: the include itself plus every nested include, a, mx, ptr, exists and redirect. Includes can change at any time; this page re-measures daily.
How it affects DMARC
DMARC passes when SPF or DKIM passes for a domain aligned with your From address. Because Postmark authenticates SPF on its own or a delegated return-path domain, alignment for your From domain usually comes from DKIM, so set up its DKIM records for your domain.
Other transactional email services
Sources
- Postmark: How do I set up SPF for Postmark? · checked 5 Oct 2026
- RFC 7208 §4.6.4: DNS lookup limits · checked 5 Oct 2026
peekip isn’t affiliated with Postmark; follow the vendor’s own setup page, which shows the exact values for your account.