We’re rewarding the question askers & reputations are being recalculated! Read more.

Questions tagged [email]

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

Filter by
Sorted by
Tagged with
83
votes
8answers
149k 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 ...
49
votes
2answers
18k 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 ...
108
votes
6answers
60k 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 so ...
27
votes
4answers
9k views

Prevent mail being marked as spam

This is a canonical question about avoiding outgoing mail being classified as spam. Also related: Fighting Spam - What can I do as an: Email Administrator, Domain Owner, or User? What ...
3
votes
1answer
3k 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 ...
69
votes
12answers
10k views

Exchange server replacement that runs on Linux

I've worked as a sysadmin for some years and what I keep coming back to is that users like Microsoft Outlook and want to use its Exchange features. I have tried my fair share of commercial ...
34
votes
10answers
46k views

How to change “From:” field for emails from Cron?

I use remote SMTP via nullmailer and it requires set From field to the specific name, but cron set it as root@my.sweet.server.com. How could I change it to something like me@ya.ru?
39
votes
8answers
30k 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 ...
42
votes
3answers
95k 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@ ...
15
votes
3answers
31k views

How to collect bounces in postfix

This is related to this question: linux - Ways to get a bounceback report for my newsletter application? - Server Fault Let's say I'm generating email addresses like this when I send out ...
29
votes
36answers
5k views

What kind of mail server do you use?

There are a lot of mail servers out there. Microsoft Exchange has been the dominant corporate mail server in the enterprise on Windows, but I've been using Kerio Mailserver for a long time now and am ...
22
votes
2answers
20k 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 ...
0
votes
6answers
774 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 ...
29
votes
8answers
2k 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 solution....
9
votes
1answer
36k 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 ...
27
votes
7answers
48k 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 /etc/...
24
votes
2answers
24k views

Is the 10-DNS-lookup limit in the SPF spec typically enforced?

My understanding is that the SPF spec specifies an email receiver shouldn't have to do more than 10 DNS lookups in order to gather all the allowed IPs for a sender. So if an SPF record has include:foo....
7
votes
3answers
15k 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 servername....
3
votes
2answers
3k views

Use different relay in postfix

In our application, we send different kind of mails. On a broad view we can generalize it in two category, Mails which monitor the health of the app. Mails which we send to end user. Is there any ...
9
votes
3answers
24k 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?
17
votes
6answers
16k 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 ...
41
votes
6answers
2k views

Is it becoming impossible to be a small mail provider?

I operate a small mail server for my private emails, some friends who have websites and two NGOs. In total my server sends between 60 and 400 messages a day. Now a lot of these emails are personal ...
52
votes
6answers
8k 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 ...
13
votes
3answers
18k 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 ...
53
votes
6answers
66k 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 ...
9
votes
5answers
16k 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. ...
7
votes
3answers
2k 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 ...
19
votes
4answers
56k views

Changing the maximum mail size in Postfix

When sending large email to a new CentOS6 server running Postfix as the MTA, the following message is returned: tried to deliver your message, but it was rejected by the recipient domain. We ...
12
votes
2answers
12k views

How to redirect all mail from one domain to another in Postfix?

I have two forms of the same domain name, one being a common misspelling of the other, let's say tedswidgets.com and tedswigets.com. I'd like to redirect all mail for <someone>@tedswigets.com to ...
10
votes
3answers
20k 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 ...
4
votes
1answer
3k views

MX Backup service [closed]

What suppliers can you recommend, that provide an MX backup service?
14
votes
3answers
30k 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?
10
votes
2answers
4k 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 ...
12
votes
4answers
25k 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, ...
9
votes
7answers
14k 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 ...
3
votes
2answers
6k 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 servers ...
9
votes
5answers
8k 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 ...
1
vote
1answer
752 views

Relase outgoing mails to internet if local delivery failes

How can I release outgoing mail to the internet if local delivery fails in postfix? My server has virtual domains configured with mydomain.tld. When I send an email to somename@mydomain.tld it try to ...
3
votes
1answer
7k views

Postfix/Dovecot - Multiple Domains and Multiple Linux Accounts

I have been trying to setup a new mail server to migrate from my VPS, as my host has decided to close its doors. The old server was running Exim/Courier (nearly a decade old at this point,) and I'm ...
1
vote
1answer
150 views

Email server configuration still complaining the connection isn't secure

This is a follow up to another question I had, but its quite different so I thought I'd start a new post. Emails bouncing - 454 TLS not available due to temporary reason I'm trying to work out why I ...
-2
votes
2answers
7k views

Postfix - How to prevent external clients from using my server as a relay? [closed]

I have a postfix server installed on Ubuntu 14.04. A PHP script running on the machine uses it to send outgoing email. Additionally, I use postfix to receive mail sent to a local account, which is ...
88
votes
11answers
175k views

How do I get apt-get to ignore some dependencies?

How do I make apt-get ignore some dependencies? For example, I wanted to install mailx so I can use it to send email from cron scripts/report-generating tools. However, installing mailx also installs ...
7
votes
3answers
20k views

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

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 mails?...
50
votes
6answers
26k views

How to Modify a Cronjob Email Subject

I am running a half dozen different cron jobs from my hosting at Hostmonster.com. When a cronjob has been executed I receive an email with the output of the script. The email comes in the format of: ...
8
votes
4answers
677 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 ...
23
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 ...
20
votes
5answers
1k 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 ...
9
votes
6answers
10k 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, ...
15
votes
3answers
13k views

Remove/hide client sender ip from postfix?

I'm trying to hide the client IP from emails sent from postfix. here is an example of what I mean: Received: from mail.[removed].com (adsl-75-37-61-254.dsl.frs2ca.sbcglobal.net [75.37.61.254]) (...
31
votes
4answers
23k views

Is using SOFTFAIL over FAIL in the SPF record considered best practice?

Or put another way, is using v=spf1 a mx ~all recommended over using v=spf1 a mx -all? The RFC does not appear to make any recommendations. My preference has always been to use FAIL, which causes ...