Questions tagged [smtp]
SMTP is the Simple Mail Transfer Protocol, the most recent standard of which is defined in RFC 5321. It's the Internet standard for sending and receiving email.
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Personal OpenSMTPd relay fails when using "tls-require", works fine with just "tls"
I'm currently setting up a somewhat unique personal email server using OpenSMTPd. I have a local server (Raspberry Pi) and a remote server (VPS). Emails sent to me are sent to the remote server and ...
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How do I tell Dovecot to use another server for SMTP?
I am a bit lost on mail servers, but I have to install a mail proxy (Proxmox Mail Gateway) in front of the actual mail server (ISPConfig, Roundcube, Dovecot, Postfix).
On receiving emails, it uses the ...
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Can't get incoming mail over TLS for Postfix SMTP Relay
I have a Postfix Ubuntu VM acting as a mail relay server, which accepts mail on port 25 and forwards it on to Microsoft Exchange online for delivery. This has been working fine for months.
Now I need ...
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Postix to relay SMTP from port 587
I have a debian server with postfix, fail2ban, roundcube, webmin and dovecot installed on it. I have been able to send mails from port 25, but regardless of what I try I can't get it to work from 465 ...
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Outlook / MS Exchange from Office 365 returns 550 header syntax
A client of mine has a case that a partner company is not able to deliver e-mails to them. The case is that they receives following information returned by Mailer-Daemon:
This message was created ...
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How do I resolve the "Snapin Error" when setting up SMTP on IIS Server?
I have installed IIS 6.0 Manager and SMTP Server. When I right-click on [SMTP Virtual Server #1] and then click on Properties, I am getting this error
"MMC has detected an error in a snap-in. It ...
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ufw configuration for smtp connections
I have a PHP application running on a Debian server with UFW as firewall. The application needs to connect to a SMTP to send mails.
It works when I disable UFW. When it's enabled, the PHP application ...
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Can't configure SMTP encryption - postfix
I have docker-mailserver and Roundcube in containers, beside there is MySQL database for mail data and user passwords. Dovecot inside is configured to verify logging in users passwords with database. ...
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Postfix still uses port 25 despite configuration saying port 587
I have a postfix server that is a relay for the main mail server.
That main mail server is to be used with the 587 port when i do a telnet on it it works just fine :
telnet 10.10.10.10 587
Trying ...
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Error setting up SMTP via Exim4
I just started at my current role and I'm the only IT guy...
I have a server that is used to send emails to a local smarthost but they just switched to using Office 365 and it "never worked" ...
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Is rejecting email based on IP address in chain allowed?
A major ISP is rejecting email (bouncing with error 550) on the basis that an IP address in the transmission chain is on their 'blocklist'. Are they allowed to do this and still be IETF compliant?
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Enable SMTP Port 587 instead of Port 25
Through my Office365 subscription, I have an SMTP relay, ‘contoso-com.mail.outlook.com’. Currently this only accepts traffic on port 25
I want to look at setting up port 587 with TLS encryption, but ...
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Using TLS1.0 or TLS1.1 to connect to Exchange Online with SMTP AUTH
I have a Windows Server 2008 R2 that is being replaced in two months. Currently we use it for sending out reports, invoices etc. with SMTP Relay from multiple applications that are also being replaced ...
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Postfix won't connect to relay SMTP server
We have a Debian virtual machine and I want to use postfix and mailutils to send email via a relay SMTP server
Trying to connect to the SMTP server with telnet works.
telnet mail.sch.gr 587
Trying 194....
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How to hide origin IP of SMTP server by tunneling/proxying incoming port 25 traffic to real mail server
We have most of our stuff behind Cloudflare.
However, some services such as mail (ex: mail.mydomain.com MX record) cannot be pushed through cloudflare and they expose our mail server's IP which makes ...
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SMTP relay with FQDN, but SpamAssassin marks FSL_HELO_NON_FQDN_1 and HELO_NO_DOMAIN
my mail provider (posteo.de) offers an FQDN during the HELO/EHLO exchange (e.g. mout2.posteo.de) – which is seen by policyd-spf (s. below) – but SpamAssassin on a receiving server marks the relay as ...
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Why does Outlook only connect to my server but not send any email?
I don't have any problems receiving email from Gmail, or any of the mailing lists that I've signed up for, but for some reason Outlook refuses to send any email to my mailserver.
_handle_client ...
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DKIM: Can I safely add a DomainKey policy record without breaking existing email?
I need to setup DKIM to validate an email provider we are using. In the provider's documentation, they require us to add two records, a selector record and a policy record, like this:
selector....
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WebApp needs to send emails via Outlook.com mail account
I have a web app running on a shared server account for the domain example.com.
The web app needs to send the occasional email to the app adminstrator.
The domain example.com is using Outlook.com as ...
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postfix: how to force IPv4 through SMTP?
Problem
I have successfully set up a Postfix mailserver with an SMTP interface, set up DKIM, DMARC, SPF, all that stuff.
But I had a problem when testing the delivery of emails to Gmail.
Namely, SPF ...
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Postfix / mailutils Mail appears to be sent in logs, but not in the mailbox
I've seen few of this question here but I couldn't find a solution for it.
I'm currently trying to set up Postfix with mailtutils, but I can't see my incoming emails in my mailbox, so I am not sure if ...
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Require authentication from subset of mynetworks in postfix
Is it possible to configure smtp for postfix to require authentication, (e.g. with smtp_sasl_auth_enable = yes), for certain IP ranges but have other ranges un-authenticated?
For our local network we ...
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Email Server with API calls [closed]
I am new to the world of Web Email and domain hosting. I was looking into projects like https://temp-mail.org/en/ and https://kopeechka.store. In these applications I can receive an email address, ...
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Compared to SPF MAIL FROM checks, what are HELO checks good for? [duplicate]
I’m starting with SPF on my (email) domain. (No DKIM or DMARC yet.)
I see little usefulness in HELO identity checking in SPF and am thinking about setting the HELO identity to my domain (instead of ...
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Setup DNS records for SMTP send-only server
I have website on hosting with domain exmpl.com.
I have DNS record for exmpl.com:
exmpl.com MX(10) mail.exmpl.com
mail.exmpl.com A XX.XX.XX.XX
exmpl.com TXT v=spf1 +a +mx +a:hosting.server ~all
All ...
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Relay access denied error attempting to setup relay to another SMTP server
I am attempting to setup 2 SMTP servers behind one firewall. One server for domainA.com and another for domainB.com. I want to configure the server for domainA.com to accept mail for domainB.com and ...
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Iptables + telnet not blocking ports
I have a Debian server from which I want to block all incoming and outgoing ports (especially all outgoing email ports), except those that I specifically add in iptables. The current setup I have is ...
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How postfix actually treats relocated_maps?
I'm close to understanding it, but one thing in documentation makes me unsure.
At first, lets take a look at postfix architecture from docs. There are two stages: receiving and delivering. During ...
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.NET program sending of email not working on client server only
I've originally asked this in SO but it seems this is a more appropriate place.
Basically, I have a program that sends email which works on my local machine and on our company's server. However, it's ...
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How to force postfix to use smtp relay
When I execute, the following line postfix uses my sendgrid relay server
echo "Subject: sendmail test" | sendmail -v [email protected]
But when I execute the sendmail function via the PHP script ...
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Graylog Email Alert Password Not Working?
I recently changed my gmail password and changed the password in server.conf as well, but now graylog's email alerting fails with:
Sending the email to the following server failed : smtp.gmail.com:587 ...
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Why is UFW blocking the smtp-plugin from Dokuwiki
I have on a virtual server (Ubuntu 20.4) Dokuwiki (2020-07-29 "Hogfather") with the SMTP plugin (Last updated on 2020-11-21) installed. My pages are delivered HTTPS encrypted, using certbot.
...
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SMTP - How to use a different IP for incoming emails
I have a send-only postfix email server where I sent emails via a command line tool
I want to be able to receive emails on a separate provider so that the staff can access the inbox
I have a temporary ...
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Office365 Connectivity Issues
I've got a 3rd party who host a system for us, it has a function to send a small number of emails for us, less than 100 a day, so we simply supplied an Office365 user to them which has been working ...
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Postfix After-Queue Content Filter full example
i'm trying the Simple content filter example: i followed the steps mentioned here http://www.postfix.org/FILTER_README.html#simple_filter
but in line 24 of the content filter that can be a simple ...
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SMTP authentication issues with Postfix Dovecot
I had bought a domain example.com and a VPS, and I used iRedMail to set up a mailserver.
Not wanting iRedMail to mess up with my Nginx, I decided to install Nginx and Roundcube by myself. However, it ...
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Relay office 365 email via smtp during migration
I am about to move users to Office 365 email from an old hosted smtp/pop system.
The domain is configured for 365 with the exception of the mx record.
I would like to create the accounts in 365 ahead ...
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Custom Return-Path for gmail domain
I do not expect my problem to be super-unique, but I was not able to find and answer so far even at Gmail help pages, and lots of googling with various terms did not provided a solution.
Context:
...
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What exactly can I conclude from "High scoring spam message has been dropped (in reply to end of DATA command)"?
I operate a web site that offers user registrations. Users get automatic registration success e-mails, sent through a professional e-mail hosting company (not directly from our own server). This has ...
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Windows 2019 and IIS Virtual SMTP Virtual Relay (Office 365)
I have hit a wall with this setup and I cant for the life of me figure this out, despite having setup a few other Virtual SMTP servers in the past. Maybe something has changed in 2019?
I will provide ...
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Postfix : "Connection timed out" on all outbound email
Aug 25 12:56:20 mail postfix/pickup[375941]: ACF7F200E248: uid=0 from=<root>
Aug 25 12:56:20 mail postfix/cleanup[376172]: ACF7F200E248: message-id=<20210825125620.ACF7F200E248@mail....
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Authenticated SMTP with sendmail on command line
we are sending emails using sendmail on the command line, with a command such as :
cat <email_contents> | sendmail -t
the <email_contents> contains fields such as sender, recipient etc.:
...
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Restrict Email Delete Access in Outlook Using Group Policy
Is there a way to restrict users from deleting email from Outlook using Group Policy or some other setup?
Or else is there any email client or provider having functionality such that admin can ...
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Opensmtpd can relay mail from a list to any domain?
My company briefly like this
I have 1500 IP addresses SMTP source and Exchange 2016 (Behind KEMP LB)
Due to LB topology, my anonymous SMTP relay receive connector scopes store on Exchange server. Now ...
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Error 500 on Digital Ocean while using SwiftMailer to send email
I am trying to send an email to myself from my seconday email address to my primary email address when a contact form is submitted to my website. I am using Swiftmailer to achieve this. The code works ...
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What is the meaning of the parameter bounce="false" in a 553 response from a receiving MTA?
This a short specific technical question about an exchange between two MTAs. It is derived from this question in Superuser, which is broader and contains some rants about technical support from ...
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Unable to connect to SMTP - "smtp.outlook.com",587 using Python2.7 from Linux server
I have a small python script below which sends emails to my company outlook email. it works fine on my personal computer but when i am deploying it to server it keeps running and timeout but doesn't ...
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Gmail reject emails sent from my domain: due to the very low reputation
We have been using our SMTP server to send emails to our clients for a few years, all of a sudden, gmail rejected them all. We have not changed anything, server is not compromised, and we don't send ...
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Tomcat Server running springboot application apruptly closes connection to smtp server
I have a tomcat server running a spring boot application on a host using CentOS 8 that connects to a mail client using SMTP. Problem is it abruptly closes connection before TLS handshake occurs with a ...
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RFC5321 and multiple RCPT TO
After analyzing https://datatracker.ietf.org/doc/html/rfc5321 I've got impression that some of its fragments contradict each other.
A single notification listing all of the failed recipients or ...