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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1answer
470 views

Postfix - sender dependent configuration based on client IP instead of email address

Using Postfix, I want to setup the transport according to the sender IP. There is sender_dependent_default_transport_maps, which does it according to the sender email address (envelope MAIL FROM). ...
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2answers
6k views

550 Invalid HELO/EHLO must contain a FQDN or IPv6

I've got a Windows Server 2008 box where I host a number of websites (on different domains) that send email as part of their functionality. I've been checking up on the SMTP events and found a number ...
2
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2answers
11k views

reason: 403 4.7.0 TLS handshake failed

Sending email to one particular domain, I get the following error: ----- The following addresses had permanent fatal errors ----- <> (reason: 403 4.7.0 TLS handshake failed.) ----- ...
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1answer
2k views

Configuring SPF, DKIM, Reverse DNS for VPS sending email through Google Apps SMTP servers

Today we realized that all of our emails being sent to email addresses of the type <username>@corporatedomain.com were getting rejected. I don't know who is hosting the email for corporatedomain....
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1answer
230 views

Setup Postfix with SMTP-AUTH over SASL2 with SASLDB for users to send emails

Hello, I spent the last few days trying to setup Postfix with SASLDB to send emails from my application over SMTP on Ubuntu Server 15.04. I searched, read and tested a lot about it but I can't get it ...
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2answers
5k views

Posfix smtpd_sasl_path seems does not work for me

I have such configuration: /etc/postfix/main.cf smtpd_sasl_type = cyrus smtpd_sasl_auth_enable = yes smtpd_sasl_path = /usr/lib/sasl2/smtpd /usr/lib/sasl2/smtpd.conf pwcheck_method: auxprop ...
1
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3answers
144 views

SMTP server force outbound traffic

I'm having some trouble with setting up a SMTP server on a windows server 2003 machine, while trying to send emails using PHP through the internet, but to domain email addresses. Common info: ...
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2answers
942 views

iptables only allow smtp connections with start tls

Is it somehow possible to block/abort unencrypted smtp connections with iptables? effectively rejecting all connections which dont do a start tls.
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3answers
487 views

SMTP for multiple domains on virtual interfaces

The setup is like this (Ubuntu 9.10): eth0: 1.1.1.1 name.isp.com eth0:0 2.2.2.2 example2.com eth0:1 3.3.3.3 example3.com example2.com and example3.com are web apps which need to send ...
1
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2answers
834 views

Set up a Postfix server on Ubuntu for use with Apple Mail (or any mail client)

I set up a Postfix server on my Ubuntu VPS and it works for sending email from the mail utility in the command line. I set up SPF records, DKIM, pretty much everything I could read about. However, I'd ...
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8answers
513 views

Best email server solutions on Windows

We are currently use mdaemon and we have over than 1000 box of email. mdaemon seen to rich is limit because is always crash. We are looking for another email server, could be exchange or other, ...
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1answer
689 views

I want Lotus Domino to only send one email to users that are both recipients and members of a cc'ed lotus group

Lotus Domino 7 and now Lotus Domino 8.5 The scenario: A@mycompany writes an email to b@internet and cc's it to group@mycompany. A@mycompany is a member of group@mycompany. With the initial email ...
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1answer
3k views

How to unassign self-signed cert from SMTP on Exchange 2010?

We have a GoDaddy wildcard certificate that we have installed into Exchange 2010 and is successfully used on IIS connections for OWA. We have assigned this certificate to the SMTP Service as well as ...
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2answers
4k views

Does SendMail Support Outbound TLS Encryption WITHOUT additions to the sendmail.mc file?

CentOS 5.x Does SendMail support opportunistic TLS "out of the box"? I'm used to having to explicitly add the following blurb to /etc/mail/sendmail.mc define(`confAUTH_MECHANISMS’, `LOGIN PLAIN’)...
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3answers
216 views

How to distribute email's delivery between 2 or more servers

We provide Email Marketing service through our online App. We have about 30 customers. And each one has it's own mailling list (5k to 20k emails each). What we really want is to distribute email's ...
1
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2answers
2k views

Spam mail through SMTP and user spoofing [closed]

I have noticed that it's possible to telnet into a mailserver that I own and send spoofed messages to other clients. This only works for the domain that the mail server is regarding; I cannot do it ...
1
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1answer
557 views

Postfix mail size counting

If I'm right Postfix counts mail size with an attachment sent to multiple receivers as one big e-mail. Eg.: User sends mail with 8 MB attachment to two receivers. Postfix thinks it's 2 x 8 MB = 16 MB ...
1
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1answer
3k views

Can I receive mail at another port like 465 instead of default 25 on my mail server?

My Zimbra mail server, which uses Postfix, is working fine. I am able to receive mail at 25 from Yahoo, Hotmail etc., but if I block my 25 port for incoming then mail will stop to come into my mail ...
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3answers
9k views

Postfix rejecting mail from authenticated clients

I am trying to configure Postfix so that it would accept mail from authenticated clients outside $mynetworks. When I try to send a test email from my iPhone, which is configured to use port 25, SSL ...
1
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1answer
68 views

No control panel equivalent of exim /etc/mailips file for configuring IPs for each domain's outgoing mail?

I have a problem with outgoing SMTP mail being sent with the wrong IP address. I use exim for outgoing mail. I found a guide "How to manually configure Exim's outgoing IP addresses", which suggests ...
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1answer
479 views

Dual delivery Google Apps and Postifx (server reject mail from my domain on google)

This is the scenario: I have a server with Postfix and some domains, and now, one of this domains want to use Gmail Google Apps only in a couple of accounts. The end-user configure the domain with ...
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1answer
1k views

How many emails per second is too fast?

I have a growing online business and a dedicated server that I use to send out the occasional newsletter. As it grows past a few thousand customers, I wonder how I can send emails faster without being ...
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2answers
4k views

What does SMTP 'designate' term mean?

I received a gmail from the address of a friend who is long out of contact. It is possible to use a utility/service such as mail2web.com to define a sender email that differs from the true sender ...
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2answers
2k views

How to share a SMTP domain between MDaemon and Exchange?

I need to setup coexistence between MDaemon (13.0.5) and a Microsoft Exchange system (Office 365); the two systems should share the same SMTP domain, and each one should forward to the other any ...
1
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1answer
648 views

What SMTP port threats to protect against?

I'm planning on creating a simple SMTP Server to auto parse incoming emails to integrate into an application. I chose this method over polling a pop3 account so that I can get instant notification. ...
1
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1answer
4k views

What is a good SMTP server for testing email system on Windows [closed]

I need a simple "fake" SMTP server or decent real SMTP server than can be configured to just dump all the mail it receives. I've tried Dumpster and it does nothing but error out on me. (I'm not much ...
1
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1answer
787 views

Exim managing bounced and failed messages

What is the best way to handle bounces and immediate failures with Exim? An email sent to a large mailing list will generate a large number of immediate failures as well as bounces. I'd like to ...
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2answers
283 views

Why does my server hostname appear in Exim email headers sent from a different domain?

I've had several problems with SMTP emails from my server and domain sent using Exim being blocked by certain other domains, which may have been partly due to certain server settings tripping up ...
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2answers
6k views

Where are the SMTP settings saved in IIS7/Win2008?

I have a problem getting SMTP to work with an ASP.NET app I have (the error I get is "Cannot get IIS pickup directory"). The app delivers the mail to SMTP using the pickup directory. I already know ...
1
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2answers
2k views

Postfix - Block email from non-existent local addresses

My question is very similar to this one, but for postfix. We keep getting emails from addresses like "accounting@example.com" delivered to our actual "@example.com" addresses. From my google research,...
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2answers
2k views

SMTP Reverse DNS Mismatch Reverse DNS does not match SMTP Banner

I wonder if you could help me? I have set rDNS to mail.simplyislam.biz for IP 178.32.48.104 with my hosting server and also in DNS control panel. However, I am still failing this test: http://...
0
votes
4answers
22k views

SMTP don't work when try to send mail from mail client

Mail server works fine when send mail from server, but when I use some mail client it not work. I found this in logs: Jul 12 19:45:04 tvsite postfix/smtpd[3356]: warning: hostname adsl-bb29-l44 does ...
0
votes
2answers
429 views

How to block IP addresses from port 25 [closed]

PROBLEM: Users are getting 15-20 SPAM emails per hour, even with SpamAssassin set to its most aggressive settings SOLUTION: SPAM filtering services are available from companies like McAfee (Intel). ...
0
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0answers
25 views

smtp-request behind iptables-router not working

I set up a router with ip-forwarding on Ubuntu 16.04 Server edition. I enabled ip-forwarding in /etc/sysctl.conf . I have set net.ipv4.ip_forward=1 and executed sysctl -p /etc/sysctl.conf I used ...
0
votes
1answer
407 views

What is a good third-party SMTP software for custom logging?

I am currently using IIS 6 SMTP to send out some of our mail and I unfortunately amn't finding the logging performed by it to be verbose enough - nor am I able to customise it to the level I would ...
0
votes
1answer
2k views

Postfix relay mails from a single domain and IP

we have an Mdaemon server which redirects outbound mails to an external basic Postfix relayer. We have configured firewall rules (in front of postfix server) to accept smtp requests only from the ...
0
votes
2answers
469 views

How can I configure sendmail (or another mail server) to accept outbound mail, but to not send it out?

Is it possible to configure sendmail to accept all outbound email but to not send it out? Either it can just log them to be read later, or better yet, if it can be configured to send ALL outbound mail ...
0
votes
4answers
7k views

Sendmail is not sending

I have a sendmail server on a Solaris 10 server that's stopped working. I can't seem to find anything about failed messages in /var/adm/sendmail. Here's what I'm seeing when I try to debug: [(root)/...
0
votes
1answer
48 views

Bizzare routing: EITHER accepts emails OR sends depending if NetworkManager is running

Due to an otherwise unrelated hardware failure (long story) I've been forced to return an older Fedora Core system into service as a mail server. It's primary service is as a file server and Samba ...
0
votes
2answers
297 views

postfix remote received header

I have two servers SERVER -1 (S1) and SERVER -2 (S2)(Based on centos 5 + Postfix). S1 contains my software and S2 is a SMTP. S1 submits mails to S2 and S2 mails to REMOTE STMP. Received mail show ...
0
votes
1answer
206 views

Require STARTTLS for sending email in exim

I have configured exim to work with dovecot (might be useful to point out) in both IMAP and SMTP auth. I need to make exim require STARTTLS + CRAM-MD5 when a client authenticates to send an email ...
0
votes
1answer
8k views

How to solve authentication error in sendmail relay through gmail [closed]

I followed the steps in http://www.linuxha.com/other/sendmail/gmail.html to setup gmail in send mail. But when I try to send mail I got the authentication failure message. —– Transcript of session ...
0
votes
2answers
3k views

Windows 2003 Server IIS SMTP Sending SPAM

we have a Windows 2003 Server using IIS6 for SMTP and Websites. A couple of weeks ago the server started to send out SPAM emails. I'm trying to figure out how to identify where the SPAM is coming ...
0
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1answer
13k views

exim configuration: 503 AUTH command used when not advertised

I'm running a piece of software on a Windows server that sends email notifications via a remote SMTP server. It has very few configuration options, and only supports basic SMTP authentication without ...
0
votes
1answer
3k views

exim4 - Why is rate limiting outbound mail to a smarthost only working with acl_not_smtp?

In an effort to rate limit outgoing emails per recipient (all emails are sent by the same user), I've been doing some testing in a very simple environment: ...
0
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4answers
2k views

Exchange 2007 server send out spam

Our exchange server is sending out spam, as it has been listed on various spam blacklist and not to sure know how to stop it. I've started with verify SMTP with a site like http://www.pagasa.net/test-...
0
votes
1answer
8k views

SMTP server works, but telnet to port 25 does not

I am running a lightweight SMTP server for processing incoming emails. I am using https://github.com/kennethreitz/inbox.py. I opened port 25 in my firewall and am running the server at 0.0.0.0:25. ...
0
votes
1answer
207 views

Failed Gmail SPF check when importing mail through IMAP from our mailbox when original email was sent with ESMTP headers

We have a strange situation: we receive an email with ESMTP headers in it our server accepts it, it's fine we import that mail in Gmail like any other emails from our boxes Gmail makes SPF check ...
0
votes
5answers
76 views

Do most SMTP servers support SSL? [closed]

I'm working on an application that has to be able to send out emails with potentially sensitive information. I was wondering if there's any data on what SMTP servers are typically used in a corporate ...
0
votes
1answer
543 views

Exim as relay server

Hi I have exim running on port 8900 and another mail server running on port 25. This mail server will be used to relay outgoing emails to exim. But somehow I am getting this error from exim 550, '...