[CentOS] [Off topic] sending mail from Comcast was: Sendmail not working

Sun Apr 19 19:09:15 UTC 2020
Jason Pyeron <jpyeron at pdinc.us>

> -----Original Message-----
> From: S.Bob
> Sent: Sunday, April 19, 2020 2:52 PM
> 
> 
> 
> I get this:
> 
> # rpm -qf `which sendmail`
> postfix-2.10.1-7.el7.x86_64
> sendmail-8.14.7-5.el7.x86_64
> 

yum erase sendmail # undo what you did before...
yum reinstall postfix # just in case it is messed up
rpm -V postfix # lets verify if postfix is ok
systemctl enable postfix # start on boot
systemctl start postfix # start it now
systemctl status postfix # see the status

# setup Xfinity / Comcast SMTP relay ISP 
	edit /etc/postfix/main.cf around line 315
	add
		relayhost = [smtp.comcast.net]


systemctl restart postfix # restart to make changes effective
systemctl status postfix # check status

echo "Subject: sendmail test4" | sendmail your_xfinity_email at comcast.com # if this works, then test outside email

echo "Subject: sendmail test4" | sendmail kevink at psalm19pix.com # does it get there?

> 
> 
> 
> On 4/19/20 12:39 PM, Jason Pyeron wrote:
> >> -----Original Message-----
> >> From: S.Bob
> >> Sent: Sunday, April 19, 2020 2:26 PM
> >> To: centos at centos.org
> >> Subject: Re: [CentOS] [Off topic] sending mail from Comcast was: Sendmail not working
> >>
> >> I followed this guide:
> >>
> >>
> >> https://pepipost.com/tutorials/install-sendmail-server-centos-7/
> > Sigh - bad examples for you.... undo if you can.
> >
> > Postfix provides the "sendmail" utility.
> >
> > # rpm -qf `which sendmail`
> > postfix-2.10.1-7.el7.x86_64
> >
> >>
> >> now I get this:
> >>
> >>
> >> # echo "Subject: sendmail test4" | sendmail kevink at psalm19pix.com
> >> [root at kdb-bugs auth]# echo "Subject: sendmail test4" | sendmail -v
> >> kevink at psalm19pix.com
> >> kevink at psalm19pix.com... Connecting to [127.0.0.1] via relay...
> >> kevink at psalm19pix.com... Deferred: Connection reset by [127.0.0.1]
> >> Closing connection to [127.0.0.1]
> >
> > What does /var/log/maillog say ?
> >
> >>
> >>
> >> Thoughts?
> >>
> >>
> >> On 4/19/20 11:08 AM, Jason Pyeron wrote:
> >>>> -----Original Message-----
> >>>> From: Tim Evans
> >>>> Sent: Sunday, April 19, 2020 12:50 PM
> >>>>
> >>>> On 4/19/20 12:38 PM, S.Bob wrote:
> >>>>> On 4/19/20 10:36 AM, Tim Evans wrote:
> >>>>>> On 4/19/20 12:28 PM, S.Bob wrote:
> >>>>>>> All;
> >>>>>>>
> >>>>>>>
> >>>>>>> I installed sendmail via yum, but if I test it like this:
> >>>>>>>
> >>>>>>>
> >>>>>>> The original message was received at Sun, 19 Apr 2020 10:02:56 -0600
> >>>>>>> from localhost [127.0.0.1]
> >>>>>>>
> >>>>>>>       ----- The following addresses had permanent fatal errors -----
> >>>>>>> <sbob at quadratum-braccas.com>
> >>>>>>>        (reason: 554 5.7.1 Service unavailable; Client host
> >>>>>>> [50.243.150.81] blocked using xbl.spamhaus.org.rbl.local;
> >>>>>>> https://www.spamhaus
> >>>>>>> .org/query/ip/50.243.150.81)
> >>>>>> Is 50.243.150.81 your system's IP address?  If so, as this shows, that
> >>>>>> IP is on spamhaus' blacklist of addresses. Thus, your sendmail is
> >>>>>> working fine.  Problem is elsewhere.
> >>>>>>
> >>>>>> anything I can do to fix it?
> >>>> Assuming this is your IP address, visit https://www.spamhaus.org/lookup/
> >>>> and request that it be removed from the blacklisted IP's.
> >>>>
> >>>> However, looking at the headers from your message, it appears Comcast
> >>>> may be your ISP, and this 50.243.150.81 IP address appears to be a
> >>>> Comcast address, so you may need to contact Comcast tech support for
> >>>> help in getting the blacklist designation removed.
> >>> There are a few situations here.
> >>>
> >>> 1. You are a business customer with a static IP, and are entitled to send/receive SMTP by your ISP
> >> (Comcast)
> >>> 2. You are a business/residential customer who is allowed to send (not likely allowed to receive)
> >> SMTP and you have a domain elsewhere to receive replies to your email
> >>> 3. You are a business/residential customer who is NOT allowed to send SMTP except for your ISP
> >> (Comcast) provided email.
> >>> Only you would know which on for sure is you, but it is very likely #3.
> >>>
> >>> The advice provided previously is for case #1 - contact Comcast and inform them that your
> contracted
> >> services are not working because of .... and you will need to beable to work with them on testing
> and
> >> suggesting fixes. They have a dedicated support phone number (which they provided you if you are
> >> actually a #1 type customer - e.g. gigabit pro, metro Ethernet, etc.)
> >>> In case you are a #2 or #3 type customer, you may want to use a smart host configuration - e.g.
> >> define('SMART_HOST','[smtp.comcast.net]') . For postfix, use relayhost = [smtp.comcast.net] .
> >>> Now when you send mail to that relay it will relay it. This is provided you are entitled to have
> >> your email relayed - contact Xfinity customer service for help there.
> >>> If using this relay does not work, please post the exchange starting with the HELO (check your
> >> maillog or do it by hand with telnet).
> >>> --
> >>> Jason Pyeron  | Architect
> >>> PD Inc        |
> >>> 10 w 24th St  |
> >>> Baltimore, MD |
> >>>
> >>> .com: jpyeron at pdinc.us
> >>> tel : 202-741-9397
> >>>
> >>>
> >>>
> >>>
> >>> _______________________________________________
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> >>> CentOS at centos.org
> >>> https://lists.centos.org/mailman/listinfo/centos
> >> --
> >> `When you say "I wrote a program that crashed Windows", people just stare at you blankly and say
> "Hey,
> >> I got those with the system, *for free*".' (By Linus Torvalds)
> >>
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> 
> --
> `When you say "I wrote a program that crashed Windows", people just stare at you blankly and say "Hey,
> I got those with the system, *for free*".' (By Linus Torvalds)
> 
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