Rainloop: Can't connect to server

I am getting this error when trying to send mails with Rainloop: Can’t connect to server.
I know there are multiple topics on this forum covering this, but for me none of these work.
My Dovecot and Postfix services are running (and starting) just fine. I added the email logs to the bottom of this topic.

Something to mention: Open Port Check Tool - Test Port Forwarding on Your Router shows my ports (like 25 and 587) are closed. Not because they are blocked by a firewall (I don’t have a firewall installed), but because there is no service utilizing them.

This is an overview of my CloudFlare configuration:

This are my email logs:

Jan 19 14:46:55 one dovecot: imap-login: Login: user=<info@mail.domain.net>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=202343, TLS, session=<d3Jnnu/VyLh/AAAB>
Jan 19 14:46:55 one dovecot: imap(info@mail.domain.net)<202343><d3Jnnu/VyLh/AAAB>: Logged out in=96 out=1013 deleted=0 expunged=0 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Jan 19 14:47:54 one dovecot: imap-login: Login: user=<info@mail.domain.net>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=202446, TLS, session=<7Er2oe/V9rh/AAAB>
Jan 19 14:47:54 one dovecot: imap(info@mail.domain.net)<202446><7Er2oe/V9rh/AAAB>: Logged out in=89 out=1003 deleted=0 expunged=0 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Jan 19 14:47:54 one dovecot: imap-login: Login: user=<info@mail.domain.net>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=202447, TLS, session=<4F/2oe/V+Lh/AAAB>
Jan 19 14:47:54 one dovecot: imap(info@mail.domain.net)<202447><4F/2oe/V+Lh/AAAB>: Logged out in=1084 out=1433 deleted=1 expunged=1 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Jan 19 14:47:55 one dovecot: imap-login: Login: user=<info@mail.domain.net>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=202449, TLS, session=<5ub6oe/V+rh/AAAB>
Jan 19 14:47:55 one dovecot: imap(info@mail.domain.net)<202449><5ub6oe/V+rh/AAAB>: Logged out in=96 out=1013 deleted=0 expunged=0 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Jan 19 14:48:54 one dovecot: imap-login: Login: user=<info@mail.domain.net>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=202604, TLS, session=<OR6Kpe/VKrl/AAAB>
Jan 19 14:48:54 one dovecot: imap(info@mail.domain.net)<202604><OR6Kpe/VKrl/AAAB>: Logged out in=1084 out=1425 deleted=1 expunged=1 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Jan 19 14:48:55 one dovecot: imap-login: Login: user=<info@mail.domain.net>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=202606, TLS, session=<j4KOpe/VLLl/AAAB>
Jan 19 14:48:55 one dovecot: imap(info@mail.domain.net)<202606><j4KOpe/VLLl/AAAB>: Logged out in=96 out=1013 deleted=0 expunged=0 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Jan 19 14:49:54 one dovecot: imap-login: Login: user=<info@mail.domain.net>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=202711, TLS, session=<kt4dqe/VWrl/AAAB>
Jan 19 14:49:54 one dovecot: imap(info@mail.domain.net)<202711><kt4dqe/VWrl/AAAB>: Logged out in=89 out=1003 deleted=0 expunged=0 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Jan 19 14:49:54 one dovecot: imap-login: Login: user=<info@mail.domain.net>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=202712, TLS, session=<Au0dqe/VXLl/AAAB>
Jan 19 14:49:55 one dovecot: imap(info@mail.domain.net)<202712><Au0dqe/VXLl/AAAB>: Logged out in=1084 out=1433 deleted=1 expunged=1 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Jan 19 14:49:55 one dovecot: imap-login: Login: user=<info@mail.domain.net>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=202714, TLS, session=<SGwiqe/VXrl/AAAB>
Jan 19 14:49:55 one dovecot: imap(info@mail.domain.net)<202714><SGwiqe/VXrl/AAAB>: Logged out in=96 out=1013 deleted=0 expunged=0 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Jan 19 14:50:02 one sendmail[202752]: 20JDo2jj202752: from=root, size=375, class=0, nrcpts=1, msgid=<202201191350.20JDo2jj202752@localhost.localdomain>, bodytype=8BITMIME, relay=root@localhost
Jan 19 14:50:02 one sendmail[202752]: 20JDo2jj202752: to=root, ctladdr=root (0/0), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30375, relay=[127.0.0.1] [127.0.0.1], dsn=4.0.0, stat=Deferred: Connection refused by [127.0.0.1]
Jan 19 14:50:55 one dovecot: imap-login: Login: user=<info@mail.domain.net>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=202852, TLS, session=<b77ArO/VjLl/AAAB>
Jan 19 14:50:55 one dovecot: imap(info@mail.domain.net)<202852><b77ArO/VjLl/AAAB>: Logged out in=311 out=1382 deleted=0 expunged=0 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Jan 19 14:50:55 one dovecot: imap-login: Login: user=<info@mail.domain.net>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=202853, TLS, session=<aNTArO/Vjrl/AAAB>
Jan 19 14:50:56 one dovecot: imap(info@mail.domain.net)<202853><aNTArO/Vjrl/AAAB>: Logged out in=1084 out=1425 deleted=1 expunged=1 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Jan 19 14:50:56 one dovecot: imap-login: Login: user=<info@mail.domain.net>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=202855, TLS, session=<ryvFrO/VkLl/AAAB>
Jan 19 14:50:56 one dovecot: imap(info@mail.domain.net)<202855><ryvFrO/VkLl/AAAB>: Logged out in=96 out=1013 deleted=0 expunged=0 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Jan 19 14:51:54 one dovecot: imap-login: Login: user=<info@mail.domain.net>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=202977, TLS, session=<37REsO/Vyrl/AAAB>
Jan 19 14:51:54 one dovecot: imap-login: Login: user=<info@mail.domain.net>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=202978, TLS, session=<LcxEsO/VzLl/AAAB>
Jan 19 14:51:54 one dovecot: imap(info@mail.domain.net)<202977><37REsO/Vyrl/AAAB>: Logged out in=89 out=1003 deleted=0 expunged=0 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Jan 19 14:51:54 one dovecot: imap(info@mail.domain.net)<202978><LcxEsO/VzLl/AAAB>: Logged out in=1084 out=1433 deleted=1 expunged=1 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Jan 19 14:51:55 one dovecot: imap-login: Login: user=<info@mail.domain.net>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=202980, TLS, session=<UxdJsO/Vzrl/AAAB>
Jan 19 14:51:55 one dovecot: imap(info@mail.domain.net)<202980><UxdJsO/Vzrl/AAAB>: Logged out in=96 out=1013 deleted=0 expunged=0 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Jan 19 14:52:55 one dovecot: imap-login: Login: user=<info@mail.domain.net>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=203085, TLS, session=</+vas+/V/rl/AAAB>
Jan 19 14:52:55 one dovecot: imap(info@mail.domain.net)<203085></+vas+/V/rl/AAAB>: Logged out in=28 out=891 deleted=0 expunged=0 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Jan 19 14:52:55 one dovecot: imap-login: Login: user=<info@mail.domain.net>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=203087, TLS, session=<P0Dms+/VALp/AAAB>
Jan 19 14:52:55 one dovecot: imap(info@mail.domain.net)<203087><P0Dms+/VALp/AAAB>: Logged out in=1084 out=1425 deleted=1 expunged=1 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Jan 19 14:52:56 one dovecot: imap-login: Login: user=<info@mail.domain.net>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=203089, TLS, session=<8/Pqs+/VArp/AAAB>
Jan 19 14:52:56 one dovecot: imap(info@mail.domain.net)<203089><8/Pqs+/VArp/AAAB>: Logged out in=96 out=1013 deleted=0 expunged=0 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Jan 19 14:54:00 one dovecot: imap-login: Login: user=<info@mail.domain.net>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=203213, TLS, session=<jM/Ht+/VOrp/AAAB>
Jan 19 14:54:00 one dovecot: imap(info@mail.domain.net)<203213><jM/Ht+/VOrp/AAAB>: Logged out in=89 out=1003 deleted=0 expunged=0 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Jan 19 14:54:00 one dovecot: imap-login: Login: user=<info@mail.domain.net>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=203214, TLS, session=<us/Ht+/VPLp/AAAB>
Jan 19 14:54:01 one dovecot: imap(info@mail.domain.net)<203214><us/Ht+/VPLp/AAAB>: Logged out in=1084 out=1433 deleted=1 expunged=1 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Jan 19 14:54:01 one dovecot: imap-login: Login: user=<info@mail.domain.net>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=203216, TLS, session=<fXLMt+/VPrp/AAAB>
Jan 19 14:54:01 one dovecot: imap(info@mail.domain.net)<203216><fXLMt+/VPrp/AAAB>: Logged out in=96 out=1013 deleted=0 expunged=0 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Jan 19 14:55:01 one dovecot: imap-login: Login: user=<info@mail.domain.net>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=203360, TLS, session=<3kRqu+/VaLp/AAAB>
Jan 19 14:55:01 one dovecot: imap(info@mail.domain.net)<203360><3kRqu+/VaLp/AAAB>: Logged out in=1084 out=1425 deleted=1 expunged=1 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Jan 19 14:55:02 one sendmail[203361]: 20JDt1aL203361: from=root, size=375, class=0, nrcpts=1, msgid=<202201191355.20JDt1aL203361@localhost.localdomain>, bodytype=8BITMIME, relay=root@localhost
Jan 19 14:55:02 one sendmail[203361]: 20JDt1aL203361: to=root, ctladdr=root (0/0), delay=00:00:01, xdelay=00:00:00, mailer=relay, pri=30375, relay=[127.0.0.1] [127.0.0.1], dsn=4.0.0, stat=Deferred: Connection refused by [127.0.0.1]
Jan 19 14:55:02 one dovecot: imap-login: Login: user=<info@mail.domain.net>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=203363, TLS, session=<csFuu+/VbLp/AAAB>
Jan 19 14:55:02 one dovecot: imap(info@mail.domain.net)<203363><csFuu+/VbLp/AAAB>: Logged out in=96 out=1013 deleted=0 expunged=0 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0

I replaced my domain to domain.net due to search engines.
Let me know if I have to add anything.

Thanks

Which VPS are you using? Majority of VPS providers these days block Port 25 relay access making it impossible to send mails via their servers. You have 2 options if that is the case, either use a third party SMTP service (which is best solution) or else open support ticket with your vps provider and request to unblock port 25 smtp relay access.

I have a dedicated server. I sent a mail to the support team, but they say they don’t block any ports. I also have no firewall enabled.
I think it’s just that the mailserver doesn’t even try to connect to the port (or it does, but on the local network 127.0.0.1)

Maybe this can help:
Host is up (0.00031s latency).
Not shown: 65501 closed ports
PORT STATE SERVICE
21/tcp open ftp
22/tcp open ssh
53/tcp open domain
80/tcp open http
110/tcp open pop3
143/tcp open imap
443/tcp open https
993/tcp open imaps
995/tcp open pop3s
1194/tcp filtered openvpn
2022/tcp open down
3306/tcp open mysql
4082/tcp open lorica-out
4083/tcp open lorica-out-sec
4084/tcp open fortisphere-vm
4085/tcp open ezmessagesrv
4123/tcp open z-wave
7080/tcp open empowerid
8080/tcp open http-proxy
8090/tcp open opsmessaging
25565/tcp open minecraft
25572/tcp open unknown
25574/tcp open unknown
25575/tcp open unknown
25576/tcp open sauterdongle
25577/tcp open unknown
25578/tcp open unknown
25582/tcp open unknown
25583/tcp open unknown
25586/tcp open unknown
25589/tcp open unknown
25590/tcp open unknown
25595/tcp open unknown
25597/tcp open unknown

Either Port 25 is blocked from your host OR
you might not have configured rDNS for your mailserver address
Or your DNS settings may have some wrong configurations.
Make sure you are not using cloudflare for your mail DNS

show the results for checktls.com
and also connect to cloud and reset email settings

Maybe worth to check your cloudflare ssl/tls security setting, that it’s not set too high.

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