csail.mit.edu SPF record

12 / 10 Lookups
2 Issues
1,291,622 IPv4 addresses
1.09 â‹… 10 29 IPv6 addresses

There are 2 issues with this SPF record

  • The 'ptr' mechanism shouldn't be used because it's slow, resource intensive, and not very reliable.
  • More than 10 DNS lookups were required to process this SPF record.
v=spf1 ip4:128.30.0.0/15 ip4:18.26.0.0/16 ip4:18.31.0.0/16 ip4:128.52.0.0/16 ip6:2603:400a::/32 ptr mx include:mit.edu ~all Copied

Terms

ip4:
128.30.0.0 / 15
pass if the sender's IP is between
128.30.0.0 and 128.31.255.255 (inclusive).
Massachusetts Institute of Technology
AS3
or else
ip4:
18.26.0.0 / 16
pass if the sender's IP is between
18.26.0.0 and 18.26.255.255 (inclusive).
Massachusetts Institute of Technology
AS3
or else
ip4:
18.31.0.0 / 16
pass if the sender's IP is between
18.31.0.0 and 18.31.255.255 (inclusive).
Massachusetts Institute of Technology
AS3
or else
ip4:
128.52.0.0 / 16
pass if the sender's IP is between
128.52.0.0 and 128.52.255.255 (inclusive).
Massachusetts Institute of Technology
AS3
or else
ip6:
2603:400a:: / 32
pass if the sender's IP is between
2603:400a:: and 2603:400a:ffff:ffff:ffff:ffff:ffff:ffff (inclusive).
Massachusetts Institute of Technology
AS3
or else
ptr:
PTR checks should no longer be used. See RFC 7208, section 5.5 .
or else
mx
pass if the sender's IP address is in the A or AAAA record of this domain.
1 IPv4 address
or else
include:
mit.edu
Evaluate this SPF record and pass if it
passes.
or else
~all
soft fail the email's SPF check.

Included records

v=spf1 ip4:128.30.0.0/15 ip4:18.26.0.0/16 ip4:18.31.0.0/16 ip4:128.52.0.0/16 ip6:2603:400a::/32 ptr mx include:mit.edu ~all
The 'ptr' mechanism shouldn't be used because it's slow, resource intensive, and not very reliable
More than 10 DNS lookups were required to process this SPF record
include:_s00430413.autospf.email -all
24 x ip4 include:_s004304130.autospf.email -all
23 x ip4 include:_s004304131.autospf.email -all
22 x ip4 include:_s004304132.autospf.email -all
21 x ip4 include:_s004304133.autospf.email -all
20 x ip4 include:_s004304134.autospf.email -all
19 x ip4 include:_s004304135.autospf.email -all
11 x ip4 6 x ip6 include:_s004304136.autospf.email -all
9 x ip6 exists:%{i}._spf.mta.salesforce.com -all

IP ranges

Massachusetts Institute of Technology
AS3
Massachusetts Institute of Technology
AS3
Massachusetts Institute of Technology
AS3
Massachusetts Institute of Technology
AS3
Massachusetts Institute of Technology
AS3
Massachusetts Institute of Technology
AS3
Amazon.com
AS16509
Mailgun Technologies
AS396479
Amazon.com
AS16509
COLT Technology Services Group
AS8220
18.9.1.0 / 24
Massachusetts Institute of Technology
AS3
Amazon.com
AS14618
Mailgun Technologies
AS396479
Microsoft
AS8075
Microsoft
AS8075
Cisco Systems Ironport Division
AS30215
Cisco Systems Ironport Division
AS30215
Cisco Systems Ironport Division
AS30215
BroadbandONE
AS7381
Rackspace Hosting
AS27357
Massachusetts Institute of Technology
AS3
Massachusetts Institute of Technology
AS3
Massachusetts Institute of Technology
AS3
Massachusetts Institute of Technology
AS3
Massachusetts Institute of Technology
AS3
Massachusetts Institute of Technology
AS3
Massachusetts Institute of Technology
AS3
Massachusetts Institute of Technology
AS3
Massachusetts Institute of Technology
AS3
Amazon.com
AS14618
Amazon.com
AS14618
Level 3 Parent
AS3549
Level 3 Parent
AS3549
Leaseweb Canada
AS32613
Mailgun Technologies
AS396479
Mailgun Technologies
AS396479
Mailgun Technologies
AS396479
Mailgun Technologies
AS396479
Florida Technology Managed Services
AS46121
Amazon.com
AS14618
Amazon.com
AS16509
Amazon.com
AS16509
Amazon.com
AS16509
Amazon.com
AS16509
Microsoft
AS8075
Amazon.com
AS14618
Microsoft
AS8075
Microsoft
AS8075
Cisco Systems Ironport Division
AS30215
Cisco Systems Ironport Division
AS30215
Cisco Systems Ironport Division
AS30215
Rackspace Hosting
AS27357
Amazon.com
AS16509
Amazon.com
AS16509
Google
AS15169
Amazon.com
AS14618
Amazon.com
AS14618
Amazon.com
AS14618
Amazon.com
AS14618
Salesforce.com
AS14340
MAILJET
AS200069
SendGrid
AS11377
SendGrid
AS11377
SendGrid
AS11377
Amazon.com
AS14618
Amazon.com
AS16509
Amazon.com
AS14618
Amazon.com
AS16509
Amazon.com
AS16509
Amazon.com
AS16509
Microsoft
AS8075
Microsoft
AS8075
Microsoft
AS8075
Microsoft
AS8075
Microsoft
AS8075
Cogent Communications
AS174
Amazon.com
AS16509
BroadbandONE
AS7381
BroadbandONE
AS7381
Microsoft
AS8075
Microsoft
AS8075
OVH
AS16276
Unitas Global
AS14742
MAILJET
AS200069
MailChimp
AS14782
OVH
AS16276
SendGrid
AS11377
MAILJET
AS200069
MAILJET
AS200069
MAILJET
AS200069
Amazon.com
AS16509
SendGrid
AS11377
SendGrid
AS11377
Amazon.com
AS16509
Amazon.com
AS16509
Microsoft
AS8075
Microsoft
AS8075
Google
AS15169
OVH
AS16276
Unitas Global
AS12182
Salesforce.com
AS14340
Salesforce.com
AS14340
CenturyLink Communications
AS3561
CenturyLink Communications
AS3561
Touchnet Information Systems
AS13450
Touchnet Information Systems
AS13450
Salesforce.com
AS14340
Mailgun Technologies
AS396479
Mailgun Technologies
AS396479
Florida Technology Managed Services
AS46121
SendGrid
AS11377
SendGrid
AS11377
SendGrid
AS11377
SendGrid
AS11377
Rackspace Hosting
AS27357
Ntirety
AS20021
Ntirety
AS20021
Unitas Global
AS11855
Unitas Global
AS11855
Microsoft
AS8075
LightEdge Solutions
AS11320
Charter Communications
AS11427
Salesforce.com
AS14340
Salesforce.com
AS14340
Salesforce.com
AS14340
Salesforce.com
AS14340
Amazon.com
AS16509
SendGrid
AS11377
SendGrid
AS11377
SendGrid
AS11377
SendGrid
AS11377
SendGrid
AS11377
Ntirety
AS20021
Microsoft
AS8075
Microsoft
AS8075
Microsoft
AS8075
OVH
AS16276
Rackspace Hosting
AS27357
Rackspace Hosting
AS27357
Rackspace Hosting
AS27357
Google
AS15169
LightEdge Solutions
AS11320
Microsoft
AS8075
Microsoft
AS8075
Google
AS15169
Google
AS15169
Google
AS15169
Google
AS15169
Google
AS15169
Microsoft
AS8075
Microsoft
AS8075
Microsoft
AS8075
Microsoft
AS8075
Microsoft
AS8075
Microsoft
AS8075
Microsoft
AS8075