sendmail domain of sender does not exist

[ReneVeerman]

hi.

i'm having difficulty getting sendmail to work

here's some output :

root@albatross:~# echo "Subject: t" | sendmail -v seductiveapps@gmail.com
seductiveapps@gmail.com... Connecting to [127.0.0.1] via relay...
220 albatross. ESMTP Sendmail 8.15.2/8.15.2/Debian-10; Mon, 16 Sep 2019 19:26:51 +0200; (No UCE/UBE) logging access from: localhost(OK)-localhost [127.0.0.1]
>>> EHLO albatross.
250-albatross. Hello localhost [127.0.0.1], pleased to meet you
250-ENHANCEDSTATUSCODES
250-PIPELINING
250-EXPN
250-VERB
250-8BITMIME
250-SIZE
250-DSN
250-ETRN
250-AUTH DIGEST-MD5 CRAM-MD5
250-DELIVERBY
250 HELP
>>> VERB
250 2.0.0 Verbose mode
>>> MAIL From:<rene@albatross> SIZE=11 AUTH=rene@albatross.
250 2.1.0 <rene@albatross>... Sender ok
>>> RCPT To:<seductiveapps@gmail.com>
>>> DATA
553 5.1.8 <seductiveapps@gmail.com>... Domain of sender address rene@albatross does not exist
503 5.0.0 Need RCPT (recipient)
>>> RSET
250 2.0.0 Reset state
>>> RSET
250 2.0.0 Reset state
rene... Using cached ESMTP connection to [127.0.0.1] via relay...
>>> MAIL From:<> SIZE=1035
250 2.1.0 <>... Sender ok
>>> RCPT To:<rene@albatross>
>>> DATA
250 2.1.5 <rene@albatross>... Recipient ok
354 Enter mail, end with "." on a line by itself
>>> .
050 <rene@albatross>... Connecting to local...
050 <rene@albatross>... Sent
250 2.0.0 x8GHQpSb006121 Message accepted for delivery
rene... Sent (x8GHQpSb006121 Message accepted for delivery)
Closing connection to [127.0.0.1]
>>> QUIT
221 2.0.0 albatross. closing connection

i couldn't find anything that fixes this situation on ubuntu via a google search, so i made this thread.

[TheFu]

A few background questions, first.
Do you own a domain name?
Did you setup DNS for the domain?
Did you setup an MX record for the email server on the domain?
Did you setup an SFP text record?
Is your email server on a commercial network or is it residential?
Do you plan to email just 1 account on gmail or every where in the world?

gmail won't accept email from unknown, unverified, domains.

Domain of sender address rene@albatross does not exist

says something is missing.

[lisati]

Is "albatross" is the name of one of the devices on your local network? If so, other email providers (e.g. gmail) are unlikely to know what to do with it, they'll be expecting something like albatross[dot]something-more.

[ReneVeerman]

i run websites for myself and other people, both on https and plain http, from behind an ADSL line.

for simplicity's sake, i'll state that i need to get two domains working; said.by (http) and nicer.app (https)

for both domains i have DNS set up with an MX record that points like everything else in the DNS setup to my outside IP of my ADSL line.

at the ADSL modem, i have port forwarding ('permit access' in my modem) enabled to send traffic to a single machine.

on that machine, i will probably need to run something like haproxy to get couchdb working,
but i think that's excess information for this thread..

i did not set up an SFP text record yet.
how would i do this?

and i need to be able to email anyone in the world from PHP and unix commandline.

also, 'albatross' is the internal name of the machine in question. nicer.app and said.by are it's external names.

[SeijiSensei]

You need to be sending from a machine with a "fully-qualified domain name" like albatross.example.com. An unqualified name like just albatross will not work.

[TheFu]

I'll await the answers to my other questions.
Thank you.

[ReneVeerman]

You need to be sending from a machine with a "fully-qualified domain name" like albatross.example.com. An unqualified name like just albatross will not work.

ok, ehm, would i specify that in /etc/hosts?

[ReneVeerman]

I'll await the answers to my other questions.
Thank you.

i think i did that earlier in this thread

[TheFu]

i think i did that earlier in this thread

Appears to me that 4 of the questions aren't answered. If you don't understand a question, that isn't a good sign. Ask and I'll try to explain.
In short, if you aren't on a business internet connection with static IPs, didn't buy a domain name and didn't buy a DNS provider to setup A, C NAME and MX records, then you won't be sending any email that will be accepted over the internet.

[SeijiSensei]

ok, ehm, would i specify that in /etc/hosts?

>>> MAIL From:<rene@albatross> SIZE=11 AUTH=rene@albatross.
250 2.1.0 <rene@albatross>... Sender ok
>>> RCPT To:<seductiveapps@gmail.com>
>>> DATA
553 5.1.8 <seductiveapps@gmail.com>... Domain of sender address rene@albatross does not exist

rene@albatross is a valid email address, but not one that would work outside a local network. For that you need a fully-qualified name with a domain part included as well.

In a telnet session to a remote mail server, you need to use "MAIL FROM: rene@albatross.example.com". You need control a valid domain and use it when composing a message. Alternatively you could use rene@example.com. How to do this depends on how your mail server is configured. Also, if you want to receive email at one of these addresses, your mail server needs to know it is responsible for handling mail addressed to @albatross.example.com or just @example.com. You need to specify both forms if you are intending to use both. See the "mydestination" directive in Postfix or the local-host-names file in sendmail.

If you're using a client like Thunderbird, you would need to specify it in the configuration for your account.

Have you registered a domain? If not, none of this will work.

/etc/hosts has nothing to do with this.