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
56 views

What are the security risks with running an SMTP server? [closed]

I'm running Windows Server 2012 and I would like to set up an SMTP server to work with my hosted websites. I've previously installed various roles on my server which have resulted in exposing security ...
0
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1answer
41 views

Postfix mail from outside not received

I am using Dovecot with Postfix and virtual user/mailboxes. Everything works fine accepting receiving mail from outside (other domains named as the mailserver) I am able to: - send mail from my mail ...
6
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1answer
69 views

Should I listen for SMTP on both 25 and 587?

I was setting up haraka as our mailing server, and for outbound email, it suggests moving to port 587 for SMTPS auth support. However, I'm unsure if I should be running 2 instances of haraka on ...
0
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1answer
83 views

CentOS postfix smtp server connection refused from outside

I am quite stuck with my postfix/smtp configuration on my CentOS machine. I setup a mail dns mail.domain.tld, configured in the postfix main.conf file and tested locally on the server by connecting ...
2
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1answer
35 views

SMTP routing cases: same @domain as sender and different @domain

I would like to know what is the difference between sending an email to the same @domain as the sender and sending to a different domain. I cant really find a detailed explanation on the web. From ...
0
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1answer
27 views

Postfix only delivering mail locally (instead of correct destination)

For whatever reason, postfix cannot send email to my google apps account. It says the message is sent, but I've confirmed with google apps support that the message isn't being received. (Thus it is ...
0
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1answer
31 views

Exchange 2007 rate limiting

I have devices on the network that send out email alerts for misc things. The other night there was a condition that caused one of the devices to send a few thousand emails to a couple of internal ...
0
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1answer
50 views

check_smtp not working when scheduled

I am trying to set up a new check in Nagios 3.5.0, making sure that my mail server is contactable on port 25 over the internet. I am using the check_smtp command. When I run this command from the ...
0
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0answers
53 views

Postfix Unable to send mail from thunderbird or outlook

OS: CentOS 6.4 64 bit Mail server: Postfix + Dovecot + MySQL + postfixadmin + Clam + Amavis I have installed a postfixmail server with dovecot,postfixadmin and mysql(virtual domains). I can send and ...
0
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1answer
52 views

postfix deliveries per connection

hope you can assist me in this case. I am administrating an Postfix server which is used for newsletters. Recently one of the major recipient domains changed their policies to only accept one email ...
0
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0answers
36 views

[Postfix/Dovecot]Impossible to send a message (smtpd)

I've just installed and configured a Postfix server with dovecot for IMAP. I've followed this tutorial for the install : http://goo.gl/Ryf49l And I've tried to connect to the server with Evolution. I ...
0
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0answers
17 views

Issue with Russian Characters using IIS6 SMTP Relay

We have an issue where we have an issue with Russian Characters in the body of emails when using IIS6 SMTP Relay on Windows Server 2008 R2. The relay points to an email provider. The characters ...
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0answers
22 views

Using mime_header_checks to ACCEPT instead of REJECT?

I'm pretty well versed in using header_checks/mime_header_checks to refuse smtp mail in Postfix, but now I think I've gone off the path of righteousness; I'm trying to suss out a way that I can refuse ...
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0answers
41 views

Outlook on Exchange: Why does it mangle return address for some email?

We have seen this too much in multiple Exchange environments, and need some guidance. When we email (using simple mail client app) to certain Exchange/Outlook sites, when those sites hit Reply, our ...
0
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0answers
54 views

SMTP on Windows Server 2008

Okay, i know that the built in SMTP server role inside Server 2008 is a little beleaguered; however, using resources here (stackex) and from msft I've worked through the issues I've been able to ...
0
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1answer
65 views

What do I need to be able to send mass SMTP email efficiently? [closed]

I am creating a web application that allows users to send broadcast emails to a list of subscribers. Essentially, it's a mass emailer and autoresponder, like AWeber or Constant Contact or MailChimp. ...
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0answers
5 views

Limit esmtp authentication on courier mailserver to certain IP addresses

I would like to limit authentication for users outside of our company network. It is possible to block authentication based on networks or by selected users? Thank you for any tips.
0
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1answer
55 views

5.7.1 relay access denied when accessing from vb.net application

I am developing a program in vb.net which needs to connect directly with my mailserver (postfix) to send emails which will be directed towards email to sms transmissions. My mailserver is otherwise ...
0
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1answer
88 views

Change SMTP server for SBS 2011 Self Monitoring Reports

SBS 2011 sends daily/weekly/instant reports from the account SBSMonAcct@. It uses localhost as the SMTP transport as being SBS Exchange is usually installed. I want to use an external SMTP server. ...
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2answers
74 views

Can MS Exchange 2010 act as an SMTP server?

We have a brand new Exchange 2010 based mail server and need to send e-mail from a remote website and some internal apps (like backup tools etc.). Can Exchange 2010 act as a SMTP server or we shall ...
0
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0answers
56 views

Incoming mail flagged as spam

A customer of my company can no longer contact us via mail. Our mailserver keeps bouncing their email as spam. I've already contacted them but they say the problem lies with our server, not with ...
0
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1answer
33 views

Allow spoofing on postfix server

I'm trying to set up help desk software which requires the ability to change the headers of a message (aka 'spoof' it). Right now, my mail server is configured to use SASL and requires authentication ...
1
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1answer
29 views

Sendmail dropping domain name from the username

I'm setting up Dovecot with Sendmail and I almost have it working (I think). The username for the account is a full email address such as "username@domain.com". What seems to be happening is that ...
1
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1answer
32 views

Simple Email Fowarding

Is there a program that handle smtp that has one and only one function: foward email from one email address to another email address? I know that this can be done using virtusertable with sendmail. ...
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2answers
110 views

Postfix, TLS and StartSSL certificates

I recently changed my postfix installation to use TLS with a certificate issued by StartSSL. I then ran SMTP and TLS checks with no errors or warnings. Everything seemed to work fine. My problem now ...
2
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1answer
63 views

Exim retry is Message based instead of host based? why

from what I understand exim retries are supposed to be HOST based, NOT message based. This seems to make sense to me; if a host's server is overloaded or otherwise telling you to "delay sending ...
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0answers
33 views

How can I prevent Sendmail from cutting off SMTP error responses from a recipient MTA in maillog?

CentOS 5.x | SendMail 8.14 I've noticed that Sendmail will occasionally cut off SMTP error responses in logs. For example: Jan 10 05:55:55 foobox sendmail[20998]: s1CStsdli020998: ...
2
votes
2answers
55 views

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 ...
0
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1answer
125 views

Postfix smtpd not listening 'Unable to Connect to SMTP Host'

I set a postfix + cyrus-sasl + cyrus-imapd mail server on my CentOS 6.5 x64 server. After I finished the settings, I found that I can send internal emails and send emails to other mailboxes like ...
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1answer
105 views

Postfix SMTP authentication per domain

Is it possible to configure SMTP authentication on Postfix with different user/pass credentials for different domains? So, I have a MTA that relays emails from ~20 different domains. When sending ...
2
votes
2answers
98 views

vps: smtp working on server client (roundcube) but cannot be configured on desktop client

I've bought a VPS and installed Ubuntu 12.04 on it. I'm using Zpanel for my Control panel and everything seems to be configured well. I can even send and receive mails on my server itself, via the ...
1
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1answer
100 views

Exchange 2010 - Unauthenticated users can send/relay local mail via telnet. How to stop this?

I'm completely new to Exchange administration. I have Exchange 2010 installed and working for the most part. The domain in question is mydomain.com. I have checked to make sure the server is not an ...
0
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1answer
104 views

Capture virtual vagrant server smtp on my actual computer

I'm running a number of virtual servers using vagrant on my computer. This is working well. I have installed Postfix to send SMTP inside these virtual servers. But what I want to do is have Postfix ...
0
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1answer
61 views

Postfix: can't send mail from remote client

I'm having issues sending mail from postfix. I believe my conf. is very standard, at the end it was put together from various guides. I'm trying to send mail from remote client (iOS Mail, and Mac OS X ...
0
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1answer
28 views

Exchange 2010 550 5.1.1 Recipient Rejected Error

About 3 weeks ago, we migrated our email solution from one hosted Exchange 2003 environment to another hosted Exchange 2010 environment. I currently have an outside user unable to send emails to our ...
1
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1answer
25 views

Exchange 2007 send as different user by default

Allow me to explain in detail. I have a client who runs 3 companies under the same roof. Each user has 3 exchange mailbox accounts (for each company domain) which they load under either Outlook 2007 ...
3
votes
2answers
81 views

SMTP: Which IP should I monitor?

I use a relay server to deliver external mails. I use relay server's IP in SPF record. But I'm not sure about blacklist monitoring/checking. Should I check main server's IP or relay's IP?
0
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1answer
61 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 ...
3
votes
1answer
199 views

Postfix client host rejected

I set up Postfix+Courier+Roundcube on Ubuntu 12.04, but when I try to send an email with Roundcube, I receive the following error: /var/log/mail.log : Dec 30 20:54:35 server postfix/smtpd[31465]: ...
0
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2answers
422 views

SMTP -> ERROR: RCPT not accepted from server: 554 5.7.1 : Client host rejected: Access denied

I am trying to send mail through phpmailer with smtp.i am using the host which i am using on my outlook with same username and password.I am getting an error .can anyone help me how to fix this. My ...
0
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1answer
48 views

Outgoing SMTP Blocked

I have an Exchange 2013 Server. My ISP blocks port 25 and it doesn't seem to be working on any other port either. I am currently using DynDNS' hosted SMTP service - but it only lets me send a few ...
0
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1answer
604 views

Postfix (delivery temporarily suspended: conversation with mydomain.net [private/lmtp] timed out while receiving the initial server greeting)

I'm running Debian 7.1, Postfix version 2.9.6, Dovecot Version 2.1.7 To set it up I followed mostly this (without the spamass-clamav-greylist bit) I have also got setup smart host relaying via gmail ...
0
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1answer
112 views

Mails sent from Roundcube on xampp not visible in Gmail,Yahoo or Hotmail Inboxes [closed]

I have downloaded and installed Roundcube 0.9.5 on my xampp server on Windows 8.It works well when receiving mails as the mails show up in inbox normally. But when i send a mail from the logged in ...
0
votes
2answers
58 views

Exim internal sending incorrect authentication

I have a problem with sending authenticated e-mails via SMTP on my hosting with CPanel using Exim. The problem occurs only when the script send (connection) is performed internally on the server. ...
0
votes
2answers
112 views

Exchange 2010 - External emails not being sent, probably an SMTP/DNS issue but need advice

I've installed and configured Exchange 2010 on Server 2012 functionally enough that I can send email between boxes on the local server. For what it's worth, I'm doing this as a test-run in a virtual ...
2
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3answers
69 views

In a linux-based email server, how can one prohibit SMTP/IMAP/POP connections from clients while still using Webmail (Roundcube)?

With a fully functioning linux-based email server (running postfix/Dovecot) how can one disable the ability to connect to SMTP/POP3/IMAP with external mail clients (or telnet, etc) while still (and ...
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0answers
128 views

Email server fails to authenticate my client, returns “use web to login”

I'm trying to send a mail message using System.Net.Mail.SmtpClient via Yandex Mail and have the following transcript: S: 220 smtp17.mail.yandex.net ESMTP (Want to use Yandex.Mail for your domain? ...
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vote
2answers
68 views

Postfix smtp for sending only

The web hosting provider of my company have a mail server with a sending limit of 300 mails a month so the idea is keep using the hosting mail for the mail spool but set up a local Debian server with ...
0
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1answer
43 views

How to override an MX value for a particular domain using a transport_maps but have some form of redundancy

I have a postfix mail server and I want to override an MX value for a particular domain. From my understanding this is can be done by the use of transport_maps ...
2
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2answers
60 views

Postfix doesn't require authentication for local emails?

I've got a Postfix/Courier mail server (Authenticated with SASL/MySQL) all according to this tutorial. I'm currently running my server on Debian 6, it is a VPS. It works well as far as I can see but I ...