ESMTP server not available

There is no way to contact the Comcast postmaster except to get removal from an IP blacklist which is not what I'm trying to do.

I am a Comcast business customer but I use my own MTA on colocated servers.  I have had trouble getting email to a specific comcast residential customer so I sent a test email and got this:

Right now these two servers are giving a temporary failure.

Dec 5 11:34:14 mta4 postfix/smtp[47602]: D933310609:
host mx2.comcast.net[2001:558:fe21:2a::6] refused to talk to me:
554 resimta-ch2-19v.sys.comcast.net resimta-ch2-19v.sys.comcast.net
ESMTP server not available

Dec 5 11:34:14 mta4 postfix/smtp[47602]: D933310609:
host mx1.comcast.net[2001:558:fe16:1b::15] refused to talk to me:
554 resimta-po-18v.sys.comcast.net resimta-po-18v.sys.comcast.net
ESMTP server not available

The email did get accepted.

Dec 5 11:34:18 mta4 postfix/smtp[47602]: D933310609:
to=,
relay=mx1.comcast.net[96.114.157.80]:25, delay=5.4,
delays=1.9/0.02/1.6/1.9, dsn=2.0.0,
status=sent (250 2.0.0 laVik9Zj50458laVkkS3yH mail accepted for delivery)

This is about the "ESMTP server not available" message.  Comcast seems to have a problem with these two servers and no way to contact Comcast to report this type of problem.

I got no bounce message.  The recipient got no email.  That is a separate issue and may be related to spam filters.  What I've read online is there is no way for the recipient to white list someone.  I'll put in a separate note on the forum on that but if anyone can help on this thread that would be appreciated.