Subject: Re: mail from mathworks.com domain is rejected

From: "Theodore Ts'o" <[email-masked]>
Date: Thu, 4 Aug 2022 12:21:47 -0400

On Thu, Aug 04, 2022 at 11:57:40AM -0400, Eric D wrote:
> I and a colleague of mine have been unable to send email to this list
> from our work accounts; the mail server always responds with the
> following:
> 
> [email-masked]
> 23.128.96.18
> Remote Server returned '554 5.7.1 <23.128.96.18 #5.7.1 smtp; 553 5.7.1
> Hello [23.128.96.19], for your MAIL FROM address
> <[email-masked]> policy analysis reported: Your address is not
> liked source for email>'
> 
> Can this be corrected? Is there any additional information that I can provide?

Mathworks.com has the following SPF settings (found by running "dig -t
TXT mathworks.com"):

mathworks.com.          900     IN      TXT     "v=spf1 ip4:144.212.130.25 ip4:144.212.244.25 include:spf-misc.mathworks.com include:spf.protection.outlook.com include:us._netblocks.mimecast.com include:_spf.salesforce.com ?exists:%{i}._spf.mathworks.com ~all"

The ip address 23.128.96.19 reverse resolves to lindbergh.monkeyblade.net.

At a guess, after expanding the indlude: fields for the SPF record for
mathworks.com, it looks like individual IP addresses that are manually
added by the mathworks.com postmaster are stored in
spf-misc.mathworks.com and spf-misc1.mathworks.com.  For example:

% dig -t TXT spf-misc.mathworks.com
	...
spf-misc.mathworks.com. 900     IN      TXT     "v=spf1 ip4:144.212.128.24/29 ip4:142.0.160.0/20 ip4:144.212.100.42/32 ip4:208.185.229.0/24 ip4:208.185.235.0/24 ip4:12.130.57.0/24 include:spf-misc1.mathworks.com ~all"
	...

So it looks like you and your colleague need to ask your work's mail
admins to add the IP addresses of the hosts from which you send e-mail
to mathworks.com's SPF allow list.  Alternatively, they may tell you
to reconfigure your mailers to use one of mathworks.com's mail
submission servers.

Cheers,

					- Ted