Servers' Reverse DNS

Hello,

Is there a particular reason why at least some of the servers’ reverse DNS do not match their forward DNS names?

*Note: As a nonnative English speaker the use of apostrophe is hard.

The IP addresses of our inbound servers do not send e-mail, therefore they do not require PTR records.

My recommended SPF record is "v=spf1 include:mxlogin.com -all"
mxlogin.com point to ony 1 IP: 78.46.158.5
Reverse DNS for that IP does not match

Perhaps I do not understand how MXroute delivers messages.

An SPF include for mxlogin.com is an instruction to include an SPF record @ the root domain on mxlogin.com, which is not the A record for mxlogin.com but is currently this:

“v=spf1 include:_s00002165.autospf.email -all”

Following that further you’ll find the SPF behind _s00002165.autospf.email reveals:

“v=spf1 ip4:185.19.31.132 ip4:216.55.99.248 ip4:216.55.104.248 ip4:23.83.208.1/20 ip4:216.55.103.248 ip4:216.55.102.248 ip4:216.55.101.248 ip4:172.82.139.0/24 ip4:159.100.240.208 ip4:46.232.183.0/24 ip4:191.252.57.0/25 ip4:177.153.0.130/32 ip4:172.255.62.1” “1/32 ip4:172.255.62.10/32 ip4:199.181.239.0/24 ip4:160.202.107.0/24 ip4:199.10.31.236/32 ip4:199.10.31.235/32 ip4:177.153.0.128/25 ip4:103.18.109.138/32 include:_s000021650.autospf.email -all”

IPs that send email are found in here, though they may not all be active at a given moment. You’ll notice that has another nested SPF under it that can be used to further locate more IPs that we authorize for our sending infrastructure.

We have a very complex sending infrastructure.

Silly me, I just verified with dmarcanalyzer.
So, the answer for my initial question is: Because it does not matter!
Thank you both!

You can use the mxtoolbox SPF record tool to trace through all the IPs yourself (follow the includes):
https://mxtoolbox.com/spf.aspx

starting with mxlogin.com.

Highly recommend mail-tester.com to see how your email looks to recipients. It’ll actually go through our infrastructure and then judge the end result, where front-end checking systems are not capable of assuming the depth of our systems.

Thanks,
I use it whenever I make adjustments to configuration

(still learning how to use the forum)