The server configuration of email, including POP3, SMTP, IMAP, and popular server software packages that control email.

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29
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6answers
44k views

How to send emails and avoid them being classified as spam

This is a canonical question about how to handle email sent from your server being misclassified as spam. For additional information you may find these similar questions helpful: Best ...
12
votes
2answers
2k views

What are SPF records, and how do I configure them?

This is a canonical question about setting up SPF records. I have an office with many computers that share a single external ip (I'm unsure if the address is static or dynamic). Each computer ...
45
votes
6answers
12k views

Fighting Spam - What can I do as an: Email Administrator, Domain Owner, or User?

This is a Canonical Question about Fighting Spam. Also related: How to stop people from using my domain to send spam? What are SPF records, and how do I configure them? There are ...
4
votes
1answer
1k views

Prevent mail being marked as spam

This is a canonical question about avoiding outgoing mail being classified as spam. I'm wondering how to prevent my emails from my site being marked as spam? I'm using sendmail. I'm trying to ...
1
vote
1answer
1k views

Outgoing mail from linux not being delivered

I can't seem to send mail through my php scripts or through the linux console on my Centos 5.5 LAMP server, when the email is addressed to go to a domain that is hosted by my box. I think it is ...
8
votes
4answers
557 views

Steps to take to improve email deliverability [duplicate]

Successfully delivering email to my clients is a pretty high priority at my company. We are of course fully opt-in, paid clients, no possibility of spam, the whole thing. The information we email is ...
6
votes
2answers
8k views

Setting up Exim to forward mail

I'm trying to setup Exim on a fresh CentOS install so that it will receive mail for a collection of given addresses, and forward the mail respectively to another address. For example, receiving mail ...
7
votes
1answer
23k views

Configure Postfix to send/relay emails Gmail (smtp.gmail.com) via port 587

Using Centos 5.4, with Postfix. I can do a mail foo@gmail.com subject: blah test . Cc: and the msg gets sent to gmail, but it resides in the spam folder, which is to be expected. My goal is to ...
7
votes
3answers
5k views

How to redirect all outgoing email from postfix to a single address for testing

I am setting up a testing server for a web based application that sends some email notifications. Sometimes testing is performed with real customer data, and for that reason I need to guarantee that ...
8
votes
5answers
12k views

How do I configure SPF for multiple domains on a server? (also allowing gmail as a sender)

SPF (Sender Policy Framework) seems like a good way to combat spammers/spoofing. However, despite reading the explanations several times, I'm not quite understanding how to configure it correctly. ...
4
votes
7answers
6k views

Acceptable load average

We deployed our new Linux/Exim/Spamassassin mail server on Friday (always a good idea to deploy the day before a long weekend when no admins are around). The load has been hovering around 1.3 on the ...
2
votes
9answers
2k views

Mail Server using Postfix

I have currently set up my web application on Amazon EC2 server. As a well known fact sending email from EC2 has a problem. As a cheap and long lasting solution instead of using "authsmtp" is it ...
0
votes
6answers
543 views

ISP blocking port 25

My ISP has started blocking port 25 so I can not send email through my dedicated server any more. I have several options: Send email through the SMTP server provided by my ISP. Any problems with ...
16
votes
6answers
13k views

How to Setup Ubuntu Mail Server with Google Apps?

I have a domain, let's call it foobar.com. All of the MX records for foobar.com point to Google's mail servers because I am using Google Apps for your domain to manage it. It's great because everyone ...
25
votes
8answers
1k views

Email hoarder intervention and education - (Exchange environment)

Throughout my career, I've encountered quite a few users who were email hoarders... I'm managing a 100-user environment where users previously had 100mb quotas and a basic Cyrus IMAP/Postfix ...
12
votes
4answers
25k views

Mail server for Windows 2008

I'm going to get a Windows 2008 dedicated server sometime soon. I'm going to have my website hosted on it, so, I also want to run a mail server on the same machine to receive any mail sent to the ...
6
votes
3answers
1k views

Email delivery management grievances

The question I have may be more of principle than anything else, but here's my dilemma. I manage an email system for a small company (about 20 email users). We own a plain-letter .com domain name ...
12
votes
4answers
9k views

Do SPF Records For Primary Domain apply to subdomains?

I have a quick question regarding SPF records: Do they need to be present for all subdomains? Lets say that I have a TXT record with SPF info for domain.com Let's also say that I have a seperate ...
5
votes
3answers
345 views

Is SPF enough to make sure emails get delivered to inbox?

So I just succesfully set up postfix + dovecot. is SPF enough to make sure emails get delivered to my website's users? I don't want my emails to end up in their spam box.
8
votes
5answers
6k views

How important are PTR records for Email Servers?

Does anyone know of any studies done to show how much email will be rejected if there is not ptr record for the SMTP banner name of an email server? Are reverse checks always done when enabled, or ...
4
votes
3answers
4k views

Configuring php mail() per domain

I have about 6 sites on my dedicated server (running centos5), and all emails sent using php's mail function are sent by nobody@servername.hostname.com e.g. "Received: from nobody by ...
4
votes
2answers
3k views

When an email is forwarded, does it lose its original headers?

I am wondering if when an email is forward does it lose its original headers?
2
votes
2answers
3k views

Postfix: send all bounce messages to postmaster

The situation is that we have a number of guests, say 80, sending through a central mail infrastructure out to the web. The way the network is setup the mail server cannot necessarily initiate ...
6
votes
3answers
5k views

How to Specify outgoing HELO with sendmail?

How do you specify the FQDN (Host and Domain Name) that a mail server presents itself as in HELO/EHLO when sending outgoing email with sendmail?
4
votes
3answers
4k views

Dovecot user lookup fails when using username@domain format

I have Dovecot v2.0.11 installed on a FreeBSD server and the user lookups for incoming email addresses are failing, but lookups for system users is successful. Dovecot is setup to use system users, ...
-1
votes
3answers
2k views

Changing hosting provider - how to migrate mailboxes? [closed]

I am going to move from one hosting provider to another. It's pretty easy to move website for me but I don't have experience with migrating mailboxes (I don't even know if this question is ...
6
votes
3answers
10k views

How do I set up a basic mail server for the first time?

I have a site running on a VPS, now I want to be able to receive mails at info@mydomain.com. How do I need to set up the server? And how should I set up the mail client on my PC to receive those ...
21
votes
4answers
13k views

Why Does hotmail still reject my emails?

I have a very strange problem with my emails being marked as spam by hotmail. I just have configured Postfix + Dovecot on my server and all works perfectly. I can Send/Receive emails. I only have ...
20
votes
7answers
2k views

Should I run my own MTA?

I need to send a large volume of emails, roughly 60.000 per week. At the moment we outsource this service to a third party, and we expect to double our volume within the next 6 months. Since the ...
6
votes
2answers
12k views

How to collect bounces in postfix

This is related to this question: http://serverfault.com/questions/20550/ways-to-get-a-bounceback-report-for-my-newsletter-application Let's say I'm generating email addresses like this when I send ...
44
votes
6answers
3k views

Why do we still have such small email attachment filesize restrictions? [closed]

What's the technical limitation preventing us, in the glorious year 2011, from emailing each other 1GB files? Or is it just the main email platforms dragging their feet? If I can set my inbox to ...
17
votes
5answers
427 views

Is it good practice or too draconian to reject mails from mailservers with no RDNS

I've recently dropped SpamAssassin and am now basing spam rejection on DNSRBL's, grey-listing and other basic tests and I'm wondering whether I should also block hosts that don't have a valid RDNS ...
15
votes
6answers
19k views

postfix - how do you redirect all emails to one user, eg *@example.com → user@example.com

I'm using postfix for my email. I know I can use /etc/aliases and newaliases command to redirect certain email, eg I can redirect root@example.com to user@example.com by putting root: user in my ...
5
votes
5answers
3k views

Is there a way to filter mails in remote IMAP account?

Situation: mail server with IMAP only access. Problem: I want to be able to filter mails (put some mails to various folders, mark them as read and so on). Most new email clients have this ability, ...
5
votes
6answers
940 views

Outsource my email server to Google

I've been looking into setting up my own email server the past couple of weeks and the more I look into it the more I feel that this is an area I do not want to get into. I guess my heart just isn't ...
4
votes
6answers
3k views

Send email on behalf of clients

We're a communications company primarily doing printing of statements / utility bills, then mailing them out in the post. A few clients have asked for e-Delivery. Pretty much take the print output as ...
7
votes
4answers
11k views

How does a Reverse DNS lookup work with regards to spam filters?

I have heard that most spam filters use a reverse DNS lookup on the originating IP address of the sending SMTP server (or something like that) as part of the verification process. I want to make sure ...
3
votes
4answers
6k views

Looking for small, lightweight, MTA

I am looking for a small footprint (in terms of processor cycles) Mail Transfer Agent for a Linux box. The box is actually a VPS server hosted at Linode. I am building the server to replace all the ...
8
votes
4answers
737 views

SPF - should I implement?

A request has been made by a web developer for our domain DNS records to include SPF TXT records. I found differing opinions on this out there... Any comments or insights you can offer will be highly ...
6
votes
9answers
8k views

Easiest way to email file via command line in *nix?

What is the easiest - and preferably most portable - command I can use to email a single file as an attachment a *nix shell?
10
votes
2answers
1k views

Cost of getting in-house certificate authority trusted

My company has an in-house certificate authority that is currently self-signed. Since we want to start using it for external SSL and secure email to our customers, we need to get it trusted. Does ...
9
votes
2answers
13k views

How should I setup separate MX records for a subdomain?

Let's say I have a domain that I run a web application on, for example cranketywidgets.com, and I'm using Google Apps for handling email for people working on that domain, for example, support@ ...
7
votes
3answers
58k views

554 - Sending MTA’s poor reputation

I am running an email server on 77.245.64.44 and have recently started to have problems with remote delivery of emails sent using this server. Only about 5% of recipients are rejecting the emails, but ...
6
votes
3answers
4k views

DNS: Is it valid to have an “MX” record and no “A” record?

Say you own a abcd.com and you only want to use it to send and receive email via bob@abcd.com. You don't want to provide any kind of website. Can you set up the DNS records to include an "MX" record ...
4
votes
2answers
2k views

Does Exchange support disposable e-mail addresses?

Sometimes it is useful to have e-mail address like foo-randomnumber@example.org, where randomnumber identifies the conversation between a robot such as a mailing list server and a user. Is this ...
3
votes
4answers
5k views

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) ...
4
votes
2answers
93 views

Confused about alias_maps and virtual_alias_maps

I have already re-read the docs on this as well as other posts here and this is still very unclear to me. I have been testing various things to understand the difference between alias_maps and ...
4
votes
3answers
769 views

Customer's IP Listed on RBL - What steps do you use to prevent black listing?

Customer called saying their e-mail was bouncing from particular vendors. Investigated it and identified they were listed on more than one RBL/CBL. Restricted firewall to only allow traffic on port ...
2
votes
3answers
3k views

How to set SPF record?

I have configured postfix to use mail.example.com I have many virtual domains, like: domain1.com domain2.com domain3.com My question is, how to set the SPF? Do I have to set SPF for each domain ...
2
votes
2answers
2k views

Configure Postfix to use external MX servers for delivery of local mail if user is unknown

I have a following setup: linux box with postfix configured to be responsible for example.com domain domain's MX servers are configured so that mail sent to example.com is sent to google mail ...