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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How can I configure my postfix server so reject_sender_login_mismatch doesn't block aliases of the main account?

I've recently setup postfix, dovecot, amavis and a suite of other tools using iRedMail, and I'm having difficultly authenticating to my outgoing mail server. The issue is this: xyz@mydomain.com is ...
4
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1answer
178 views

Simple, forwarding-only MTA?

I have a domain and a server. I’d like to have some e-mail addresses on the domain and I’d like to forward them elsewhere. I’d love to avoid running a full-featured MTA on the server, since they’re ...
4
votes
1answer
1k views

postfix misconfigured: “mail for (domain) loops back to myself”

I've just installed postfix on my debian system, so I have a default configuration, apart from the following values in /etc/postfix/main.cf: myhostname = mydomain.com alias_maps = hash:/etc/aliases ...
4
votes
1answer
4k views

Dovecot - Unable to receive mail - Fatal: Plugin 'sieve' not found

Struggling to Dovecot/Postfix set up on Ubuntu 11.10, Dovecot version: 2.0.13, Postfix version: 2.8.5 I can send outbound mail using the mailx command, but I can neither receive mail or send mail ...
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1answer
2k views

Exim TLS and Secure SMTP

I'm in the process of converting an existing mail server to support encrypted SMTP for our clients, but I've run into this brick wall with very little useful log data to help me forward. Everything ...
4
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1answer
176 views

Hot/Lukewarm mail server setup

We have two mailservers ("dubone" and "dubdeuce"), one does all the work while the other sits idle. We want to have a setup where if dubone is busy or down, dubdeuce can accept/reject/filter emails ...
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2answers
2k views

How to remove the SMTP address for a secondary domain from all Exchange mailboxes?

I have an Exchange server which used to manage multiple SMTP domains; now it only has to manage one. I have already removed the secondary domain from all address policies; I need to remove all SMTP ...
4
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1answer
404 views

Is null return path reliable indication of a bounce?

I have a mailbox that receives bounces as well as normal email (the latter includes messages from automated services). I want to filter out the bounces and forward them to another mailbox. Assume I ...
4
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1answer
2k views

Load balancing SMTP in a way that doesn't hide the source IP address

I need to load balance SMTP to handle some applications that don't know how to use MX records. I set up a Netscaler using the TCP option on port 25 and now Exchange sees the source IP as that of the ...
4
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3answers
582 views

How to limit amount of email sent by postfix to certain domains and control it by using mail header?

Goal I'm looking for a solution to limit rate of e-mails sent to specific e-mail operator (several Top-Level domains, all of them I know) on hourly basis. I also need some way to control the rate on ...
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2answers
386 views

Creating a “fake” open relay to capture non-relayable outgoing mail with postfix

We occasionally have customer-provided servers in our technical support and engineering departments. They're isolated on their own VLAN, with strict firewall rules in place to minimize possible bad ...
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1answer
2k views

Mail queue retry interval practices

I'm configuring a custom made mail queue. The thing is there can be errors sending mail. Normally, one won't know the reason why the mail didn't reach it's destination. So the most simplistic solution ...
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8answers
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Emails are being rejected by some email providers

I have this asp.net application that sends out emails. The SMTP server is iis6. The emails are being sent on behalf of our application users and they have different domain names. Most of the email ...
4
votes
1answer
171 views

how do I set up two smtp ports for postfix?

A CentOS 7 server with postfix, dovecot, and mailx needs to accommodate mail being sent through port 465 and received through port 25. What specific syntax and files need to be changed in order to ...
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2answers
553 views

Security Risk involved in disabling SMTP authentication on POP3 Server?

I provide IT Services to a client who, for the longest time in the world, has been using a POP3 server from Network Solutions to handle their email. At this time, I'm introducing the McAfee SaaS ...
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2answers
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Are there any SMTP servers that support the SMTPUTF8 extension? [closed]

RFC 5321 limits email addresses to 7 bit US-ASCII encoding. RFC 6531 (a fairly new spec) allows email addresses in SMTP commands and IMF headers to be encoded in UTF-8. This SMTP extension makes ...
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1answer
313 views

Does DKIM works with subdomains?

ISP's recommend you segment your marketing and transactional emails by using different IPs. I want to start using DKIM, but since DKIM is a domain based reputation system I wonder if signing with the ...
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2answers
1k views

Using DHCP to push SMTP server addresses to clients

I noticed on the Windows DHCP service there's an option to add SMTP servers to the information provided to DHCP clients. I've never heard of this before, but it sounds useful, especially for when our ...
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6answers
886 views

How to legitimately work around ISP rate limits

A lot of ISP rate limit the amount of e-mails that is sent from a particular IP address. What is the proper way to get around that rate limit? Our company has an iPhone application that sends many ...
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3answers
5k views

Trouble with IIS SMTP relaying to Gmail

I appreciate that similar questions have been asked about how to setup SMTP relaying with IIS's virtual SMTP server. However I'm still completely stumped on this problem. Here's the setup: IIS 6.0 ...
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votes
2answers
4k views

Mac OS X Server (10.5) mail trapped in queue

We've got mail accumulating in our Leopard Server's queue and not sure exactly why. This machine has required little maintenance over the years so I'm hoping someone here spot the obvious and save us ...
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2answers
4k views

How to read the “MS ForeFront” antispam report in email header?

I'm trying to diagnose why emails I'm sending out from my server's IIS SMTP Pickup Folder are getting bounced back occasionally. One tech from a receiving company who couldn't receive the emails ...
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3answers
185 views

Exchange 2007 - One server set-up

I'm trying to set up Exchange 2007 with just one server (not the Transport + Hub configuration, just a Hub). I installed the server with the Hub Role, and it's not accepting SMTP. I changed SMTP so ...
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2answers
955 views

How to copy outgoing messages on sendmail

I've searched the serverfault and Google, but did not find anything related to my question yet. So, I have a customer that wants to read all emails sent by his employees. I've configured a VPS with ...
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3answers
393 views

Postfix + Php Mail() VS Postfix + SMTP

Most CMS (Joomla for example) comes with php mail() as default and has the option of changing it to SMTP if we want. I will be setting up both the webserver and mail server (Postfix) in the same VPS ...
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1answer
2k views

Flood of traffic on port 25

I am getting thousands of hits on port 25, over 400,000 connections in a day. I am using sendmail default settings on Debian 7. Mailserver is not configured. Please see below Nginx access logs ...
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6answers
709 views

Monitoring incoming email server

What do people use to monitor that their email server is accepting external email? Most monitoring solutions send notices by email which is useless when incoming email breaks, so some other method of ...
3
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1answer
136 views

SMTP errors with iOS devices

I'm trying to diagnose why when an iOS device like an iPhone or iPad is set up to use email with our server for the first time, these errors occur. We choose "Other" from the initial set of choices ...
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2answers
22k views

Easiest way to configure local SMTP server to relay through gmail on Windows?

We have gmail for our corporate email provider. I want to be able to send mail through smtp.gmail.com from ASP.NET. I have managed to do this just fine - and it has the benefit of all sent items ...
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2answers
68 views

Postfix SMTP Relay Configuration Error

For the last day I was searching for solutions for this problem: My postfix(+dovecot) configuration is fully able to receive e-mails and to serve them via IMAP but it fails at accepting them via SMTP ...
3
votes
2answers
334 views

Change or spoof outgoing SMTP server name

Having a strange problem here. We send out emails from a web application that use an SMTP server setup on a Windows 2008 R2 server. Everything was working fine but one of our customers changed their ...
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3answers
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Has anyone used Amazon Simple Email Service (SES) and if so does it have standard SMTP configuration?

We want to use the more advanced features of Amazon SES such as their API for having better control and visibility over emails. However I also want it to work OOB with our current system which is ...
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3answers
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Unauthorized email is sent using google apps registered domain

I have a domain name 2m.lt registered and added to google apps. There is an option there that all the email adressed to my domain (*@2m.lt) is forwarded to my mail email account (admin@2m.lt). Well ...
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4answers
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SMTP relay through GMail overrides “from:” address with “[me]@gmail.com”

I've been trying to figure out if this is a new "feature" or if there is an issue with my configuration. I'm using Ubuntu 10.04 Desktop with Postfix as MTA. My smtp (as opposed to smtpd) ...
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6answers
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Push email to a apache/php server

We've built a web service that needs to check constantly for email messages. Basically, an user sends us an email, and the server should make actions based on that email. We could use a crontab PHP ...
3
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2answers
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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?
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2answers
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postfix for sending emails thru php?

I want to install postfix (apt-get install postfix) to be able to send email thru php mail(); But i don't get does postfix needs an smtp to send emails or he can do it on his own? (because if it ...
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3answers
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Multiple PTR records

In your experience, have you found there to be any actual problems with having redundant PTR records (same name, multiple IPs) for a given host? Additionally, would you expect to see corresponding A ...
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2answers
338 views

How secure is our companies SMTP server if the PHP MAIL function can use it?

My company has just switched from having our e-mail hosted through a web hosting company to hosting it ourselves. I have been using PHP's mail function for forms on our website and because the web ...
3
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1answer
771 views

Changing HELO name in Exchange 2003

When I telnet to my mail server on port 25, I get the following: 220 myownmaiil.com My question is, how do I correct the spelling mistake in the mail? My mail server is Exchange 2003
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4answers
305 views

Minimize the chance my email is blocked/filtered as spam

I'm running a web-based store where order confirmations are sometimes blocked and don't reach the intended user. The structure of the business model is such that our product is marketed to the ...
3
votes
1answer
331 views

Port25.com SPF test fails, gmail SPF pass

When testing my SPF record using port25.com's nifty little tool by sending an email to check-auth@verifier.port25.com I get the following FAIL result: ...
3
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1answer
426 views

Change Outgoing SMTP port in Exchange 2003 with a slight twist

I feel like I should know this, but its been a long week already. I have a customer with an SBS Exchange server on their LAN. They currently have their MX going to Postini, who is then delivering the ...
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1answer
2k views

How to add DKIM feature to the IIS 7.5 - Windows Server 2008 - DomainKeys Identified Mail

How to add DKIM feature to the IIS 7.5 - Windows Server 2008 DomainKeys Identified Mail
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votes
6answers
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What is causing email sent from my Google Apps account to bounce?

I have started to get Delivery Status Notification (Failure) messages in response to emails sent from my Google Apps domain account (at offby1.net): Delivery to the following recipient failed ...
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2answers
565 views

Set up an SMTP server that catches & stores all mail

I need to set up a SMTP server in a dev environment that will accept all mail sent to it (for any domain) and simply store it so we can later see what it has caught. What is the easiest way to set ...
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2answers
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SMTP 552 4.3.1 Session size exceeds fixed maximum session size

I'm having a frustrating problem with one of our clients who is running an exchange SMTP server. I have an emailing component that is written in .net and I've specifically used Mono DLL's to ensure ...
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2answers
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SPF Setup - Sending from VPS and Google Apps

In follow up to my question here, how on earth do I setup a SPF record?!? I understand that I have to add a TXT record to my DNS entries but what to put in that TXT entry is what's confusing me... I ...
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7answers
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What are the possible causes of this error: “Unable to > connect to ssl://smtp.gmail.com:465”?

I'm getting this error on my local machine when sending emails using (gmail's smtp + PHPMailer + CodeIgniter), which I wasn't getting on our previous office (we had to move offices). Severity: ...
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5answers
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How can I set up sendmail to forward all mail to an external MTA?

We have multiple applications that currently talk SMTP to an external MTA. The emails have arbitrary destination domains (they're emails to be sent to our users), but all from the same internal domain ...