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

learn more… | top users | synonyms (1)

6
votes
2answers
4k views

E-mail addresses with plus sign in MS Exchange [duplicate]

Possible Duplicate: Does Exchange support disposable e-mail addresses? Many users like to use e-mail address in the format "[user]+[tag]@[domain]" to facilitate local filtering of incoming ...
6
votes
2answers
616 views

Exim backscatter

One of my relays has been listed on backscatter.org, now I'm trying to configure our existing config only to send bounces to local users only. Does anyone knows how I deal with this issue? I've added ...
6
votes
1answer
53 views

How Does Low Volume Affect (esp. live.com) Email Deliverability?

I've been sending emails for years with out any serious reputational shocks, but with low IP volumes (no bulk mail or automated transactional email), even with multiple Domain names. My Gmail ...
6
votes
2answers
928 views

How switching off SSLv3 in Courier-IMAP server affects old Mail User Agents?

I would like to mitigate POODLE vuln. in my courier-imap server. I know how to do it. I'm really concerned on how it will affect MUA's, especially the older ones. There are still users using Outlook ...
6
votes
2answers
2k views

Get individual message size for all Exchange 2010 users

I need to make a report with a list of the largest messages on an Exchange 2010 server. I looked through the commands that I could use, and Get-MailboxStatistics isn't granular enough - I need to find ...
6
votes
1answer
3k views

Applying ACLs to a Dovecot public namespace

I would like to provide access to some mailing lists via a set of public, read-only mailboxes in Dovecot. I have a public namespace define in my dovecot (dovecot-2.0.9) configuration that looks like ...
6
votes
1answer
1k views

How to edit bad word filter in SpamAssassin?

How can I add several custom "bad" words into SpamAssassin, so emails that contains that words are marked as a spam? UPDATE one of the keys is to edit file /etc/mail/spamassassin, and to add badword ...
5
votes
8answers
5k views

Should our company allow employees to forward their Exchange email to GMail?

Many developer prefer the GMail interface and thus forward (actually pull) all their email to GMail. Assuming we trust Google, are there any reasons why this should be disallowed? Edit: Interesting ...
5
votes
7answers
9k 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 ...
5
votes
10answers
3k views

How to recover outlook emails

It has happened many times in my organization that some people have left in not really good terms. So when you go to check their computers you find that they normally delete their emails, sometimes ...
5
votes
6answers
2k views

Email notification about each SSH connection to Linux server

I would like to be notified about each SSH connection to the Linux (Debian) server. Already saw some methods, which proposed to add mail command into own .bashrc, but this approach seems not to cover ...
5
votes
6answers
1k 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 ...
5
votes
3answers
5k views

How should I test Clam Anti-Virus?

I have setup a new email server and now I need to test that Clam Antivirus is scanning messages correctly. How should I do this in a safe and controlled way?
5
votes
5answers
10k views

AOL is rejecting emails from my client's website, how can I troubleshoot?

I am a bit of an email noob. My website is trying to send email from a contact form using the PHP mail function. This works fine when sending it to my Gmail account, but AOL rejects it. I have set ...
5
votes
3answers
1k views

Email Attachment Size Limits

Given I have plenty of disk space to work with, what are some technical considerations that I need to consider when configuring email attachment size limits?
5
votes
4answers
4k views

How can I configure my server to notify me whenever it is remotely accessed via ssh?

I need to be notified by email when my Ubuntu server is accessed via SSH. If it is possible, how can I do it?
5
votes
2answers
5k views

Why an empty MAIL FROM address can sent out email?

We are using Smarter Mail system. Recently, we found that hacker had hacked some user accounts and sent out lots of spams. We have firewall to ratelimit the sender, but for the following email, the ...
5
votes
4answers
7k views

Do i need to open 25 port to send emails with the php mail function?

I have a Linux web app. Do I need to open port 25 to only send emails using the PHP mail function? If I have to open port 25, how can I disable receiving emails? Edit: I am asking because I ...
5
votes
3answers
394 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.
5
votes
3answers
9k views

Does anyone have real-life examples of e-mail being intercepted?

As anyone will tell you, e-mail is not secure. It travels around the Internet in plain text and we should not use it for sending passwords and other sensitive details. For years I've been designing ...
5
votes
4answers
3k views

How to send 100,000 emails weekly and avoid being considered spammer

I have a mailing list with 100,000 email addresses, and I have to send it an email weekly. What application/program/webapp/script/etc do I have to use to send 100,000 emails weekly and avoid being ...
5
votes
1answer
183 views

Is an MX record needed?

We have a testing server with its own domain name. We don't want any email to be sent from this domain. We don't want any email to be received on this domain. Is it ok to remove the MX record ...
5
votes
5answers
1k views

Demanding your clients to change extensions from .zip to .txt for mail attachments

A company we are working with has a few ridiculous security measures. One of them goes like this: You cannot e-mail us .zip files. If you want to transmit a .zip file, rename it to .txt. IMHO, ...
5
votes
6answers
2k views

Prevent outgoing spam

What are some ways to prevent spam from leaving your servers should a hosting account get compromised? Have a bunch of clients on a server with cpanel but wondering if there was a way to just ...
5
votes
5answers
4k views

Does it really matter what your server's hostname is?

I'm kind of hesitating if I should use a subdomain or just a plain word as hostname. E.g. my domain name is domain.com and my server's hostname ip1.domain.com. This might be a strange question but ...
5
votes
2answers
395 views

What is push email?

Looking for a true technical explanation on this.
5
votes
1answer
9k views

Office 365 routing of internal domain messages

Our office uses both office 365 and Google apps. We were on Google apps first, and decided to give office 365 a try. Some folks liked it, some did not, and want to revert back to Google apps for mail. ...
5
votes
2answers
3k views

Postfix: How to accept email from a specific non-existing domain?

We need to accept email from a server that sends out using a non-existing domain. That server is not under my control. In my main.cf I have smtpd_client_restrictions = permit_mynetworks, ...
5
votes
4answers
2k views

ptr for a subdomain

I’m feeling lost in DNS; please help me get back on track. I’ve got a domain. Let’s call it example.com. And I can add DNS entries for subdomains of type A and CNAME. I have another server which I ...
5
votes
1answer
4k views

Full status information in Nagios email notification?

I have set up Nagios to monitor my servers and I have written a few custion checks. When I get a notification email, I only get the first line of the status information and I have to use the web ...
5
votes
3answers
507 views

How to get Postfix statistics of second instance?

I have a quick question. I have two instances of Postfix running on an Ubuntu server and I want to write some scripts to email our server admin Postfix statistics (queue count, sent, etc). How would I ...
5
votes
3answers
7k views

Linux: Send email to another address instead of /var/spool/mail/root

I manage a micro linux server on Amazon EC2. Occasionally I get email sent to the root account and if I'm logged in, I'll get the notice: You have new mail in /var/spool/mail/root How do I get ...
5
votes
4answers
3k views

Reject incoming emails that use your own domain as sender

It would be nice to reject incoming emails which use one of my virtual domains as sender address while not being a legitimate user of mine. I know that I can reject incoming emails which use an ...
5
votes
3answers
99 views

What to do if one doesn't want to receive email bounces?

Background—the standards RFC 5321 §4.5.5 states: All other types of messages (i.e., any message which is not required by a Standards-Track RFC to have a null reverse-path) SHOULD be sent with ...
5
votes
2answers
692 views

Perfect Forward Secrecy (PFS) for mail servers

Perfect Forward Secrecy is an important enhancement to SSL/TLS communications, helping prevent captured SSL traffic from being decrypted even if the attacker has the private key. It's easy enough to ...
5
votes
3answers
10k views

Sendmail: Sender address rejected (Domain not found)

I'm running into problems with sending mail on our webserver. Some mails are sent and delivered without any problems (eg Gmail), while others are deferred with "Sender address rejected: Domain not ...
5
votes
4answers
4k views

Can an e-mail's headers tell you if it has an attachment?

I'm trying to filter emails that have attachments, but in the system I'm using I only have access to the headers (for filtering). Is there a consistent way of determining if an e-mail contains ...
5
votes
2answers
5k views

Does the presence of a Content-ID header in an email MIME mean that the attachment must be embedded?

Two different third-party email products we have are reacting differently to the presence of a content-id header in the MIME source of an email. This is resulting in an inconsistent user experience ...
5
votes
1answer
5k views

Exchange 2010: Log in to another user's mailbox with an admin user that does not have a mailbox

We have Exchange 2010 users that are part of the following Exchange groups: Organization Management Server Management However, these accounts do not have Exchange mailboxes. We could log in to ECP ...
5
votes
2answers
306 views

Can spammers extract valid email addresses from my mail server?

I have a 12 letter and number email address. The email address have never been used on the web or have been used to send email to others, yet I get spam on it. This has happened to me on both Linux ...
5
votes
2answers
5k views

Refuse to send email to specific recipients with Postfix

So, right now I am halfway through trying to setup an outgoing-mail blacklist, by way of smtpd_recipient_restrictions. The problem I am experiencing is that my test emails are being delivered when I ...
5
votes
2answers
2k views

Custom headers in Email lost?

I have some questions about custom mail headers Does anybody know of any mailserver which deletes proprietary/custom headers when being transmitted to its destination? Is there a header you can set ...
5
votes
4answers
2k views

Free calendar server? [closed]

I am looking for free calendar server who can authenticate to LDAP server. I want our users to use thunderbird lightning with calendar server. We have mail server with devcot and squirlmail for ...
5
votes
1answer
550 views

Does anyone recognize this e-mail sniffer or malware using ROT13 encoding?

I have a private website that every week sends e-mails with two different http links to a group of around 30 people. When a link is clicked, the answer is registered in a database. Starting last week, ...
5
votes
1answer
236 views

Does the MTA (Postfix, Exim, etc.) get installed seperate from the mail server

I'm new to mail servers and still trying to understand all the components. What I read is that there are many MTAs, but the 4 common ones are qmail, Postfix, Sendmail, and Exim. I also found this ...
5
votes
6answers
9k views

Emails going to Junk for Hotmail recipients [duplicate]

We send daily mass emails to our customers (~30,000+ emails per day). We have problems with Hotmail users receiving our emails. Sometimes the email goes to the Junk folder, but often it will got to ...
5
votes
6answers
4k views

How might I stop BACKSCATTER using qmail?

I have a Linux box acting as Virtual Host for domain hosting. It runs CentOS and Parallels Plesk 9.x. Regardless of the following, the SPAM keeps flowing in at 1-3 / second. An explanation of the ...
5
votes
12answers
8k views

Personal email archive alternative to PST files

If you aren't willing or able to prevent users from keeping old emails "forever", what solution do you have? Exchange 2007 allows pretty massive mailboxes, but lots of people still recommend against ...
5
votes
1answer
5k views

t-online.de blacklist “host refused to talk to me” (BL)

I got following error message for several days, as my server tried to send a message to an emailadress at t-online.de: host mx02.t-online.de[194.25.134.9] refused to talk to me: 554 IP=xx.xx.xx.xx - ...
5
votes
1answer
3k views

Turn of amavisd notifications about UNCHECKED content to postmaster

How do I turn off "UNCHECKED contents in mail FROM" mails send by amavis to the postmaster of the domain every time a user sends an encrypted mail. The setup is a Debian 7 with postfix and amavisd.