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

Sun Apr 19 19:47:32 UTC 2020
S.Bob <sbob at quadratum-braccas.com>

my relay will be smtp.fastmail.com and it requires authentication and 
SSL, are there added settings in main.cf that will allow this?


Thanks



On 4/19/20 1:09 PM, Jason Pyeron wrote:
>> -----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
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> CentOS mailing list
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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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`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)