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Questions tagged [smtp]

SMTP is a protocol built upon TCP/IP, used for outgoing email transmissions, and email relaying. It uses ports 25 (clear) and 465 (SSL) by default.

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16 views

Closing port 25 for SMTP when using Gmail via Postfix

On my server, I need to send email via Postfix. The SMTP settings are as follows and these work. Email is sent via Gmail properly: relayhost = [smtp.gmail.com]:587 smtp_use_tls = yes ...
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0answers
12 views

Is There any Method Of Automated Delisting Blacklisted IPs for SMTP Servers?

IPs for SMTP servers get blacklisted all the time, and it's painstaking to get them delisted manually, especially if you got dozens or hundreds of SMTP servers to manage. So can we hope for any ...
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7 views

Milter for Sendmail not sending data over socket - very little documentation, any ideas?

I have configured Milter for sendmail on a virtual machine. I can send an email in my test environment, it is currently accepted by Sendmail and relayed to my exchange server (including when I enable ...
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1answer
72 views

Protecting an email-proxy (Gmail) account being used by a Mail Transfer Agent (MTA)

On Debian LAMP with different PHP based CMSs I use the MTA sSMTP to send email via an email proxy (Gmail); the emails I send are only contact-form inputs transferred from any such CMS to my own email ...
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0answers
79 views

How to install Postfix in an all default way (no setup wizard) and to be used with no email DNS records?

The following question is a follow up to this question. In a latest Debian 9 stable I desire to install Postfix to send email from my machine to my very own Gmail account by the quickest install ...
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2answers
123 views

Understanding sendmail binary

I have a website with some PHP based CMS on which I'm the only user. This website has a simple contact form (name, email, phone and body) by which I get mail from non registered users. I'd like to ...
2
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3answers
172 views

Why does cron use MTA to send emails, while we use MUA to send emails?

I have looked at the definitions of MTA, MUA, MDA, for example, https://ccm.net/contents/116-how-email-works-mta-mda-mua and https://en.wikipedia.org/wiki/Email_agent_(infrastructure) In Lubuntu, the ...
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2answers
50 views

Auto-notify when postfix requires TLS?

I've set up postfix on CentOS 7, and configured it to require STARTTLS to accept incoming mail. I've run into a couple instances where a server doesn't, for whatever reason, support TLS encryption, ...
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1answer
382 views

interactive SMTP command using telnet via a shell script

I'm trying to access a SMTP remote server thru a remote shell using telnet and a command file command.txt containing command to send to that SMTP server as seen on https://tecadmin.net/ways-to-send-...
2
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2answers
171 views

Configure Postfix to Send Mail Using Gmail in Ubuntu 16.04

I have configured Postfix to Send Mail Using Gmail. I have modified the file /etc/postfix/main.cf adding myhostname = fqdn.peris.app mydestination = $myhostname, peris.app, localhost, localhost....
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2answers
2k views

Ubuntu 18.04: Error with mailx smtp - mailx: unrecognized option “-S'”?

I was trying to send an email to multiple persons using mailx (mailx (GNU Mailutils) 3.4). I did that successfully on a previous version of Ubuntu, v16.04, and the script was working fine. Now I have ...
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0answers
584 views

CentOS 7 Firewall: How to allow SMTP outgoing emails with IPTables?

I am running a Spring-Boot Java application inside a Docker container on a server running CentOS 7. [root@dev-machine ~]# rpm --query centos-release centos-release-7-5.1804.4.el7.centos.x86_64 I ...
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1answer
43 views

Does an SMTP Server have to be reachable from outside our networks

We have an environment set up with VMs and docker container. Now I have installed an SMTP Server with PTR Record bind to an IP and on the IP there is an VM running with a docker container on which ...
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1answer
177 views

Mailgun SMTP protocol doesn't send emails

I use a script where I can manage mail configuration for Mailgun. Configuration seem to be OK but the register mail doesn't send from Mailgun logs. I can use SMTP or sendmail or email protocol. I ...
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1answer
1k views

How do I correctly configure exim4 on Debian so I can use `sendmail -t` to send mail via my office365 account?

I'm using Debian stretch (9.4). I have an office365 account. Using Evolution, I can successfully download mail via POP3, and also send mail using the Evolution "Sending E-mail" preferences: Server: ...
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2answers
1k views

How to send mails using SMTP server in Linux without error

I'm trying to send mail via SMTP server. And set /etc/mail.rc file with: set bsdcompat set smtp=smtps://smtp.gmail.com:465 set smtp-auth=login set smtp-auth-user=user@gmail.com set smtp-auth-password=...
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1answer
132 views

exim4 smtp connection to rogers.com

I'm trying to set up exim4 on my Debian/Buster server to work with my new ISP (Rogers.com). They require an SSL connection on port 465, which isn't unusual, but I can't get it to work. They do require ...
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1answer
237 views

iptables: Logging connections on port 25/TCP

I have KVM virtualization. I have over 60 interfaces: vnet1-60 - virtual; vmbr0 - bridge; enp2s0f0 - PHYSOUT; I need to know how many connection make each vnet interface. I have a rule like: ...
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1answer
278 views

Alpine with hotmail | SMTP | cannot send email

Dear Unix and Linux Community, I would like to use my hotmail account through alpine. I am using the POP3 protocol, and I am able to access the email from my Inbox. However, I am unable to send any ...
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1answer
49 views

mail should come with sender name not from root

When I am sending mail by using below command in RHEL 7.4 server, I am receiving mail from root@<server name with fqdn>. echo test|mailx -S smtp=mail.sap.corp -s "test" -v venkatesh....
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4answers
410 views

A utility to email myself if my site is down

I use Ubuntu 16.04 with Nginx and a few WordPress sites. Sometimes I don't visit a site for a long time (>=1 month) and it might be that the site is down. I'm looking for a small utility that will ...
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0answers
153 views

I used to be able to use gmail to email a file from my linux SBC, but now I'm getting an error

I used to be able to send files using: mpack -subject <somefile> me@example.com but now I'm getting the following message: sendmail: Cannot open smtp.gmail.com:587 My /etc/ssmtp/ssmtp.conf ...
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2answers
183 views

Different Outputs for MX Toolbox Port Scan and nmap

I am looking at which ports are open for a smtp host (this host is not mine), and I am seeing different outputs for each of two tools (MX toolbox port scan and nmap). The nmap scan shows that port 465 ...
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1answer
63 views

ssmtp myaddress@gmail.com < file.log doesn't work. Body is blank

I'm running a simple rsync script where I log stdout and stderr to two different files, rsync_stdout.log and rsync_stderr.log. When I'm trying to email the content of rsync_stderr.log using: echo $(...
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0answers
113 views

Tips for Troubleshooting Remote IMAP/SMTP Host Connection with OPENSSL and NMAP

I work in tech support for a company that has an email inbox integration. Users can input IMAP and SMTP host names and ports and we will attempt to open a connection with those ports and host names so ...
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1answer
233 views

Sendmail is periodically sending emails [closed]

The exchange mail server showed that there is a server is sending emails with 17000+ emails in queue. After blocking the server from sending emails, we investigated the outgoing traffic using ...
0
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1answer
219 views

SendGrid SMTP integration with Snipe-IT asset management

I am trying to implement SendGrid SMTP integration with snipe-it . I am testing out both applications on a vmware player with centos7 . i have successfully setup snipe-it and now trying to test ...
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0answers
532 views

SASL Authentication failure

Created an user with # adduser username The configuration file /etc/sysconfig/saslauthd: # Directory in which to place saslauthd's listening socket, pid file, and so # on. This directory must ...
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1answer
1k views

SMTP relay check (test) (Postfix)

I want to add item/trigger to Zabbix to check that some server A can send mails via mail server B (SMTP relay) without sending on real/fake email and I haven't a problem with firewall/iptables rules ...
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1answer
328 views

Cannot connect to SMTP server [closed]

I'm unable to establish a connection to my server's SMTP server, it gets closed immediately. telnet x.x.x.x 25 Trying x.x.x.x... Connected to xxxxxx.xxx. Escape character is '^]'. Connection closed ...
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0answers
454 views

Centos Email Server Unable to Send Email

I have a Centos 5 box. My server is running plesk. Individual domains are able to receive emails on plesk created email accounts. However, my server is not able to send emails. I tried to use php ...
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0answers
67 views

Connects to sendmail, but can't send letter

I have installed sendmail to my linux local server (RHEL 6). I'm trying to send letter via my client by THE BAT to other user SMTP connection successfully establishes! But letters wont'go. I looked ...
1
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1answer
360 views

OpenSMTPD Pipelining not supported messages

I'm using OpenSMPTD 6.0 (6.0.2p1-r2 installed from alpine repository) in docker container to send emails from PHP app. Everythings works OK but from time to time I see the following messages in ...
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2answers
161 views

Alpine failed to connect to port 587

I have smtp-server=mail.domain1.tld:587/user=user1@domain2.tld/ssl in my .pinerc. When I try to send, alpine 2.21 complains SSL negotiation failed and suggests that I add 'notls' to the server name. ...
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1answer
562 views

How to enable SMTP forwarding?

I am using a university server that runs linux (Ubuntu 16.04). I am trying to use this server to send email messages (using python, code below), but apparently outgoing SMTP connections are blocked (I ...
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1answer
476 views

How to configure my linux machine to send emails from terminal [duplicate]

How to configure my linux machine to send emails from terminal. I tried the following apt-get install postfix mailutils sudo systemctl start postfix echo "Email Text" | mail -s "Subject" "user@...
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1answer
1k views

Mutt | SMTP session failed: 553 5.7.1

I'm trying to set-up my aol mail to work with mutt. I can read my messeges but can't send/reply. All I get is this message: SMTP session failed: 553 5.7.1 : Sender address rejected: not owned by ...
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3answers
2k views

How to send raw mail message on Linux?

If I have the full contents of a MIME message, what is the best utility on Linux to send the message? The MIME message would include the full headers and mail body, for example: Received: (qmail ...
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1answer
32 views

Why is an SMTP service running by default after the install?

I can see that localhost:25 is by default used after an install on many Linux distributions. Why is this for? My hint is for to deliver local system-generated mails?
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2answers
137 views

Can the “\” character in the PTR record be allowed?

When I connect to my WiFi router (TIM) my machine is logged on the internal DNS to the router and the PTR with the value: MBP-di-Antonio.homenet.telecomitalia.it. I get the PTR value via the command: ...
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1answer
142 views

postfix dual interfaces, isp1 port 25 blocked, fast, isp2 port open, but slow

Ciao! How are you? ​​Problem: I need 2 interfaces, because the fast ISP blocks 25 port, the slower is open. ​​I can telnet with the required interface: telnet -b 192.168.81.20 alt2.gmail-smtp-...
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1answer
288 views

Postfix - send all notify_classes except failed authentication

How do I configure Postfix/Dovecot to not send errors to the postmaster regarding failed authentication? A botnet continually hammers my server, and I end up with hundreds of these emails: Transcript ...
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0answers
419 views

Send mails on Ubuntu 16.04 - Failed to authenticate on SMTP server with username using 3 possible authenticators

I'm trying to send mails on my ubuntu server (from gmail). I have the Starter Cloud package from Scaleway. I have installed sendmail on my ubuntu server with the following tutorial. In my Laravel ...
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0answers
196 views

Whitelist certain IP in Debian postfix/courier mailserver

On a debian wheezy mailserver with postfix an courier I want to whitelist certain IPs, that are blocked somehow (those IPs are from an openvpn provider) so I can send out mails with that server. I ...
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1answer
3k views

OpenSSL s_client not detecting STARTTLS

I am trying to fetch the certificate of my mail server with s_client $ /opt/local/bin/openssl s_client -starttls smtp -connect corti.li:25 CONNECTED(00000003) didn't found starttls in server ...
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2answers
7k views

Problem sending email using ssmtp

I am attempting to setup so I can mail from Raspbian. When I attempt to send I get an error ssmtp: Cannot open smtp.gmail.com:587 (I also tried port:465) I have set "Access for less secure apps" on ...
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1answer
957 views

Cannot send email via postfix / dovecot error status=deferred (mail transport unavailable)

I am trying to setup a mail server with postfix/dovecot/maria DB on centos 7 and have seem to hit a roadblock. I am not able to send emails to internal users and the logs suggest "mail transport ...
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1answer
566 views

How to use multiple Exim SMTP AUTH methods (dovecot and plaintext)

I would like to configure Exim to allow SMTP AUTH logins using the same credentials as for a Dovecot IMAP server on the same machine, but I would also like to allow additional sets of credentials so I ...
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1answer
4k views

Sendmail SMTP “My unqualified hostname” and “My unqualified domain name”

Recently, I've been setting up an SMTP mail server for my website (ironfi.st) on a server titled "ironfist-droplet". I'm using the WP-SMTP-MAIL plugin. I have the apache2 server setup up and ...
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1answer
612 views

Sendmail SMTP not working on apache2 server [My unqualified host name (X) unknown]

I recently did a task for my development team's website (ironfi.st), in which I set us up an SMTP mail server on an apache2 web server. I used sendmail to complete the task along with a WordPress SMTP ...