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Lookups
1
Issue
2
IPv4 addresses
2
IPv6 addresses
The 'ptr' mechanism shouldn't be used because it's slow, resource intensive, and not very reliable.
Terms
a
pass
if the sender's IP address is in the A or AAAA record of this domain.
1 IPv4 address
1 IPv6 address
or else
mx
pass
if the sender's IP address is in the A or AAAA record of this domain.
1 IPv4 address
1 IPv6 address
or else
PTR checks should no longer be used. See
RFC 7208, section 5.5
.
or else
-all
fail
the email's SPF check.
Included records
v=spf1 a mx ptr -all
The 'ptr' mechanism shouldn't be used because it's slow, resource intensive, and not very reliable