SPF record question

Hi.  I have spf record quesiton.  My mail is hosted by zoho mail.  I have no issues there.  But I have an AS400/iSeries that I am sending out emails nightly to customers with shipping info.   For example those emails are coming from S103jmr4.xxx.com (xxx being our domain name).  The idea I believe is to add an spf record with that special name in it so that people will receive those emails, but I want to make sure that people keep receiving the normal mail.    I used an spf builder to create a record using the S103jmr4.xxx.com.  But does that spf need to include info about the zoho mail server too?
Here is the spf record created.
xxx.com.  IN TXT "v=spf1 mx ptr a:s103jmr4.xxx.com ?all"

Kevin CaldwellOwner of RUseeingRed Tech SolutionsAsked:
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Jan SpringerCommented:
any mail server needs to also have both matching forward and inverse DNS.

I would add it as an "ip4:" and optionally as an "a:".

and, yes, your spf for your domain should include all valid outbound email servers/ip addresses.
If you have a SPF record for your mail domain, it should include every source that legitimately sends email for your domain.  So, yes, include the details for zoho as well.

Side note: unless the IP at s103jmr4.xxx.com changes, I would just make your SPF record reference that IP.  Often the mx and ptr are frowned upon for inclusion in the SPF record, but it may make sense depending on your setup.
Kevin CaldwellOwner of RUseeingRed Tech SolutionsAuthor Commented:
Where we are is very remote and only have verizon wireless as the connection.  We do not have a static ip so the public IP could change.
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nociSoftware EngineerCommented:
if no other mail sources are allowed a -all might be preferable above ~all.
It should reduce sending backscatter related spam  (sent in your name).
DrDave242Senior Support EngineerCommented:
But does that spf need to include info about the zoho mail server too?

If that zoho mail server is included in your domain's MX records (which should be the case if it's handling inbound mail to your domain as well), it's already covered by the mx mechanism in your SPF record.

I'm with footech on the recommendation to remove the ptr mechanism, especially if the IP addresses of any of your sending servers may change.
nociSoftware EngineerCommented:
All potential mail sending AUTHORIZED servers need to be in the SPF.
That can be done through: IP4:/IP6: records for raw addresses, A: records to get hostnames translated.
or mx to also include all MX mentioned servers. (This only helps if your ALL outbound mailserver are also handling inbound mail).
If strings get too long you can use include: or redirect: ...
Also there is a limit to the (extra) lookups you may cause: max 10..., this can be an issue if refering to includes/redirects.

PTR is not terribly useful as those DNS records should translate ip address back to strings. and you need IP addresses.

Here you can check if the result is meaningfull:

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