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.
589
questions with no upvoted or accepted answers
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IIS SMTP TLS encryption issue
I enabled TLS in IIS SMTP Virtual Server with a self-signed server certificate. Made sure that the certificate has the FQDN of the server. Checked the TLS encryption checkbox in Virtual SMTP > ...
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How can I explicitly disable TLS when sending to one specific recipient?
I have a SendMail 8.14 server deployed in the middle of an SMTP workflow (Outbound mail looks like Exchange -> SendMail -> Appliance -> Internet)
I have TLS configured for the first three hosts. ...
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When does Postfix not perform lookups in virtual_alias_maps?
I'm having a real pickle of a problem:
I have a Postfix 2.6.6 / CentOS 6 server that's set up to forward mail from specific aliases to specific destinations. This is done through a mysql ...
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3
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1
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Configuring mailiers in Phabricator
After a clean installation using the bitnami image I followed the instructions to set up the mailers.
It looks like this:
[
{
"key": "stmp-mailer",
"type": &...
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votes
0
answers
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Why is Exchange 2010 SMTP not rejecting external messages to internal-only groups?
TL;DR: How do I make sure that the SMTP server doesn't accept external messages for distribution groups that are set to require authentication?
I have an Exchange 2010 server that has multiple ...
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2
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Can't find the IP address of a Saslauthd login attempt
I need help locating the origin IP from this error messages/ login attempts:
From the 'sasl auth daemon' via Logwatch:
pam_unix(smtp:auth): check pass; user unknown
pam_unix(smtp:auth): ...
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3
votes
1
answer
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Is it possible to change sendmail behavior on "Host unknown" errors?
Sendmail 8.14.4
I had DNS issues resulting in a DNS server thinking that a hostname wasn't available (when in fact, it was available).
That resulted in the following delivery log entry in sendmail:
...
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3
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0
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Don't send outgoing mail via Spamassassin
My e-mail server is running Postfix 2.11.3 on Debian 8.7 (Jessie) with Spamassassin 3.4.0.
I realized that my outgoing e-mails are also being checked for spam, which not only seems to be unnecessary ...
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3
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0
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Combating a persistent spam list
We use Office 365 as our primary mail provider. We have an internal mail server that we use for relaying things like reports from our SSRS, scan to inbox for old scanners, etc. It is an IIS SMTP on ...
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3
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1
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SMTP authentification request transfer to another SMTP
I'm having an issue that's above my competence level. As we're working on improving the security measures that are in place in our network, we found (among others) one flaw that we have no idea how to ...
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3
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Postfix STARTTLS works in LAN but not externally
if I connect in LAN on port 25 to my mail server, it offers STARTTLS
telnet mailserver.com 25
Trying 192.168.0.x...
Connected to mailserver.com
Escape character is '^]'.
220 mailserver.com ESMTP ...
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3
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hMail Server SSL Certificate Verify Issue | TLS/SSL handshake failed
I will tell you my situation step by step and ask me any necessary questions and help me to fix hmail certificate issue.
First of all :
1-
i am using a windows server 2008 - r2
2-
latest hmail ...
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3
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0
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Outlook.com rejects: 550 SC-001 (BAY004-MC5F13)
I am operating a cluster of 3 dedicated machines for a webapp, each of those uses sendmail as MTA. Hostnames are node1.domain.com node2.domain.com node3.domain.com
Unfortunatelly outlook.com rejects ...
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3
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1
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Exchange 2010 is trying to relay messages for delivery
I am using Exchange 2010 on premises. I am in the process of setting up a SMTP proxy that will receive all messages coming into the office, log them, then forward them to my exchange server for local ...
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How to identify the user/computer that is relaying spam through a mail server?
For the past couple of days, at certain intervals, a huge load of email is dumped on my Exchange 2003 server and relayed out until it gets blacklisted everywhere.
Nothing like this happened for many ...
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1
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What are the values of Exchange's XSHADOW and XQDISCARD commands?
Shadow redundancy is an Exchange-specific feature (beginning with Exchange 2010) that provides a measure of fault tolerance when relaying email messages with SMTP.
The sending Exchange server sends ...
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3
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Mail relays or SMTP services for use in code
I'm looking to start using an SMTP or mail relay service. I've found quite a few out there, but I'm not sure if there are advantages to one vs another. The only requirements I have are:
can send "...
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2
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1
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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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0
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How does Postfix define an unlisted recipient or sender?
Postfix's documentation defines smtpd_reject_unlisted_recipient (default: yes) as
Request that the Postfix SMTP server rejects mail for unknown
recipient addresses, even when no explicit ...
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Exim: Redirect mails without spooling
I am running a personal mail server using exim that only forwards mails (and also runs a few mailman mailing lists).
Unfortunately, my server’s spam protection is worse than that of the mail provider ...
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2
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1
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Windows Server 2019 SMTP Server - Email Stuck in Queue / Not Being Released
I've recently upgraded a number of servers from Windows 2008 R2 to Windows Server 2019. 2 of the servers require SMTP which I have installed on both, however, 1 server works as it should and the 2nd, ...
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Sendmail - convert 500 fatal errors to 400 temporary errors - possible?
I run a couple of email relay hosts at work. A number of customers use ProofPoint as email washers, so their MX record in DNS is something like mxa-002d7b01.gslb.pphosted.com which washes the mail ...
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2
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1
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Mail blocked from Windows Server 2016, but not since 2008
Good Morning:
I'm running exactly the same script from two different virtual machines:
The first in Windows Server 2008 R2
The second in Windows Server 2016
Features
The SMTP is an external ...
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2
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0
answers
385
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Connecting to a external exchange server via linux/php?
We have an SMTP relay available that we are using on windows servers.
[mail function]
; For Win32 only.
; http://php.net/smtp
SMTP = email.relay.url
; http://php.net/smtp-port
smtp_port = 25
...
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2
votes
1
answer
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SMTP MTA to MTA authentication
I still have trouble understanding how a receiving MTA authenticates the forwarding MTA.
I imagine an email that is forwarded by domain A's MTAA to domain B's MTAB.
Steps to take by MTAA:
Find MX ...
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2
votes
0
answers
524
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Postfix transport based on source IP address (with or without relayhost)
We have Postfix relay server running on centOS 7.4.
Restricted source IP address by mynetworks cidr
mynetworks = cidr:/etc/postfix/allowlist.cidr
Now, I like to configure, some of the source ip ...
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2
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0
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HAProxy - IMAP, SMTP, POP3 - Multiple Servers
Please accept my apologies if this is off topic or does not apply on a more broad scale (i've searched the internet and can't seem to find a solution anywhere). I'm not sure if this is even possible, ...
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Postfix: Script to difference hard vs soft bounces
I followed the steps mentioned in the forum - how to collect bounces for triggering a script upon a bounce receipt. Now, I would like to classify the bounce depending on the status. It would be ...
2
votes
1
answer
543
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Reject Exim authentication attempts based on username
Is it possible to set up Exim so that, based on the username passed along to it, it can reject an authentication attempt before it will try to do a password lookup for that username? I've done similar ...
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How is an SMTP-Client supposed to behave if he receives an Error from the Server?
Consider the following SMTP-Session:
220 mx.example.com ESMTP Postfix
EHLO example.com
250-mx.example.com
250-PIPELINING
250-SIZE 10240000
250-ETRN
250-STARTTLS
250-ENHANCEDSTATUSCODES
250-8BITMIME
...
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2
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Prevent postfix from trying secondary MX after soft bounce from Google MX servers
My local SMTP relay is finding it increasingly difficult to deliver mail to my G-Suite groups and users. The volume is not very high, but Google enforces rather low limits on incoming e-mail from ...
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683
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With a period/dot in the name part of the address, Domino 9 SMTP won't accept incoming mail
Summary: Receiving mail to [email protected] works, but [email protected] doesn't.
On an IBM Domino 9.0.1, a proper Global Domain document exists for the domain foo.com
One user has two email ...
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2
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1
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Receiving mail from Gmail delayed - PTR issue?
One of our partners receives our mails with noticeable delays. The same mail sent to two addresses under their domain are sometimes delivered at their server hours apart (checked in the actual server ...
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2
votes
1
answer
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"Fetching" SMTP connections
I'm struggling to word this question so please bear with this preamble.
We use a product called Serv-U from Solarwinds as an sFTP server as it has a gateway feature I find really handy. The server ...
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2
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1
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4k
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SMTP load balancing with remote host's IP passed through to SMTP servers?
I'm attempting to build a load-balanced SMTP cluster. The mail servers already exist and run Exim 4. Initially, I looked at using Nginx to do the load-balancing, however on the test system all the ...
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2
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Exchange 2013 Banner
We have an exchange 2013 server that is failing a reverse SMTP Banner Check:
220 [Internal IP] ESMTP Smtpd;
I have gone into our exchange receive connector for the internet, "Default frontend ...
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2
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0
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Postfix doesn't send email, only receive
I recently install on my Debian Server the PostFix + Dovecot + Mysql, everything works fine, but I cant send email, I receive the error on the log
NOQUEUE: reject: RCPT from unknown[##.4.##.41]: 454 ...
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0
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vCenter email notification has a semicolon/SMTP does not recognize it as a valid email address
Messages from vCenter has this header info:
Received: (from root@localhost)
by (8.14.3/8.14.3/Submit) id u92F2su5032029;
Sun, 2 Oct 2016 15:02:54 GMT
Date: Sun, 2 Oct 2016 15:02:54 GMT
...
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Postfix permit localhost use plain login
I have postfix 2.11 setup on Debian jessie with Dovecot SASL and I require encrypted login mechanism to send mail via smtp. For this purpose in the main.cf I've smtpd_tls_auth_only = yes option set. I'...
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Setting up nginx to proxy (adding SSL) SMTP with authentication
In my organization we are migrating a certain web+mail setup, and I think that maybe nginx can be suited to do what I want, but I cannot fully understand the official documentation.
I have a certain ...
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2
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1
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Catch incoming email and then deliver to original recipient on sendmail
in the company I work for there are a user that is making bad use of the email, but to have evidence of what he is doing we need to intercept all the incoming email to him and all outgoing email from ...
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Does Google require TLS on port 587? Exchange 2010 SMTP has mail sent to GMAIL backed up in queue
Exchange 2010 SMTP has mail backed up in queue. Any email sent to Gmail sits in the queue while any email sent to another personal domain which has email filtering enabled errors,
"asp.reflexion.net ...
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0
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Getting "5.7.1 Unable to Relay" intermittently on mails sent to Exchange 2013
I have a helpdesk system that sends mails through the local exchange server. Until a few days ago, I never had issues with it.
For the last week we have started getting complaints about missing ...
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1
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6k
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Configure Citadel to be Used For sending email using smtp
Sorry for this foolish question, but I have less knowldge about servers. So bear with me!
I have configured Citadel as directed in linode documentation and can
login using the front-end for accessing ...
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2
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2
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how to Dedupe email messages in exim mail server (Linux)
If a User is listed in multiple aliases or multiple mailing list or groups a message is sent to more than one of the aliases, mailing list or group the end User will receive multiple copies.
How to ...
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1
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2k
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Exim SMTP Smarthost Setup
I used these settings to set up exim to use gmail as a smarthost, which worked. However, I don't seem to be able to use these settings against other smtp servers, such as Yahoo or Fastmail (both with ...
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2
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1
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Postfix: don't bounce for remote rejects
I'm having a problem with sending bounces to spammers when a remote "trusted" smtp server rejects a mail. My server manages mail for company1.com that has a virtual alias [email protected] that ...
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0
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How to access Apache Tomcat running on Windows Server 2012 (alongside Microsoft SMTP service)
I am running Apache Tomcat as my only HTTP server on Windows Server 2012.
Tomcat has been installed as a service and is bound to port 80. The server.xml file has had address="0.0.0.0" added to the ...
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4.4.1 Timeout in 10 minute intervals SMTP on batch email jobs
I am running a job that uses SMTP and it can run in excess of an hour, emailing the entire time. It's not my code but a workflow based app so I just get a form to configure the mail server, subj, msg, ...
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2
votes
1
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SMTP Event Sinks in Windows 2008 R2
We use a 3rd party software to send Bulk Emails. The software does not provide options to add Email addresses in BCC. However, as per Compliance Rules, it is necessary for us to add a BCC address to ...
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