dusko + mailserver + sysadmin   109

How to prevent spoofing aka forging - Sendmail
: In sendmail, how to prevent external (outside domain users) persons
: to access the aliases? I have included many mailing lists in terms
: of /etc/aliases but those mailing lists may have the potential to
: be spammed by outsiders. How to do in cf level to reject those
: mails from OUTSIDE domains but to accept from the organizations
: or selected sites?

I implemented the following hack exactly for that purpose when our
internal distribution lists got hit by spam. I'm sure it could be
easily adapted to meet your needs.

Add the following to your m4 master configuration file: ...
sendmail  mta  mailserver  spam  sysadmin 
2 days ago by dusko
modoboa - Mail hosting made simple
Modoboa is a mail hosting and management platform including a modern and simplified Web User Interface. It provides useful components such as an administration panel or a webmail.
mailserver  postfix  dovecot  mysql  mariadb  python  sysadmin 
5 weeks ago by dusko
Modoboa - Mail hosting made simple
A solution to quickly deploy and manage a complete email server, compatible with latest standards and optimized for delivery and reputation protection.
mailserver  hosting  sysadmin 
5 weeks ago by dusko
SMTP Gateway - Free SMTP Gateway - XEAMS - eXtended Email And Messaging Server
Pricing for SMTP Gateway
There is no charge for the software. It is free for both commercial as well as non-commercial use.

SMTP Gateway is a free SMTP server that can be used either as a backup server to your primary email server to provide load balancing. Its built-in queue holds messages until the primary server comes up. Hence providing an uninterrupted e-mail infrastructure for any company. SMTP Gateway provides a web-based administration allowing users to modify configuration and monitor its status remotely from any machine.
mailserver  mta  backup  sysadmin 
9 weeks ago by dusko
[CentOS] Re: How to size an email server to handle 5 million emails per day
On Thu, Jan 03, 2008, Joshua Gimer wrote:
>I can only talk from experience; we are currently doing spam and anti-virus checks in our inbound flow of around 600,000 messages per day.
>To do this we have three inbound SMTP gateways running Sophos Puremessage with Sendmail as the MTA. These systems are quad proc systems with 6 to 8 GB of ram. This is still not enough to handle the inbound flow efficiently at our organization.
sendmail  mta  smtp  sysadmin  mailserver 
september 2018 by dusko
Sendmail - NST Wiki
How To Flush Out All Email Messages From The Sendmail Queue

Sometimes email messages can be queued up with the Mail Transport Agent: "sendmail". The following command line can be used to manually try to immediately flush out All emails queued up by "sendmail". Even though a "sendmail" service may be running, this command is Ok to use, it will only run once and then terminate.
Try To Flush Out The Entire "sendmail" Queue:
[root@probe-222 root]# /usr/local/sbin/sendmail -q -v
sendmail  mailserver  sysadmin 
july 2018 by dusko
Sendmail Evolution
Gregory Neil Shapiro and Eric Allman
sendmail  mailserver  sysadmin 
july 2018 by dusko
example_mail Cookbook
A Chef cookbook to setup a proper mail server for production usage.
Sources for this Cookbook

https://dokuwiki.tachtler.net/doku.php?id=tachtler:postfix_centos_7

https://dokuwiki.nausch.org/doku.php/centos:mail_c7:start

Mad props to those two links above. Thanks the documentation of these two guys, most of this configuration was possible and is indeed shamelessly copied from their links above.
mailserver  sysadmin  devops 
july 2018 by dusko
Sendmail Delay?
By default sendmail sends out a queue runner every 5 minutes. The default Timeout.hoststatus is 30 minutes, which means if a timeout occurs attempting a delivery (a temporary failure) that host will be ignored for 30 minutes, even though queue runners are being sent every 5 minutes. You might try playing with the Timeout.hoststatus settings - confTO_HOSTSTATUS in sendmail.mc and send out a couple of queue runners to see if you can clear the queue more quickly.
sendmail  mailserver  mta  sysadmin 
july 2018 by dusko
MJML - The only framework that makes responsive-email easy
MJML - The only framework that makes responsive-email easy. Framework to create amazing emails.

Drop in Components
- lists
- carousel image slider
- social share buttons
- invoice
- Tables
- Location
- Buttons
- Navbar
- Hero heading

GitHub - https://github.com/mjmlio/mjml
Project - https://mjml.io/
Docs - https://mjml.io/documentation
Examples - https://mjml.io/templates
Generator - https://mjml.io/try-it-live
Image - https://www.apollowebstudio.com/screenshots/2017/mjml-email-template-framework.jpg
mailserver  email  sysadmin 
april 2018 by dusko
Symbiosis - An easy-to-use hosting environment developed
What is Symbiosis?
Symbiosis is an easy-to-use hosting environment developed at by the team at Bytemark. The design goals were to invent a way of managing a server that was easy to use, but integrated well with Debian GNU/Linux.

Features
We recognised the need to balance the need for ease of use with running cutting-edge websites, and reliable email handling.
mailserver  sysadmin 
march 2018 by dusko
The beginning of the end of the private mail server
Thanks to overzealous filtering by mail relays, the small mail server is becoming an endangered species. ---- Posted on Dec 8, 2014.
mailserver  sysadmin  smtp  spf 
march 2018 by dusko
Complex Sendmail Structure
PROBLEM: Convert mail from PMDF to sendmail.
Current environment is a single mail server, running PMDF, with /var/spool/mail NFS mounted on >40 machines.
This must be replaced with a sendmail environment, with two servers, no NFS.

In order to convert the handling of email from PMDF to sendmail, and to completely reconfigure the mail environment, several dependencies had to be met. They were:

1) All Mail leaving the company must have usernames rewritten to first.last
2) All mail bound internally must have the sender address remain uname@company.com, but the recipient must be rewritten to first.last@company.com.
3) There must be two mail machines. One machine must handle all rewrites, aliasing, and Majordomo lists. The second machine must house the mail spool, and otherwise be ignorant of any rewrites. They will be referred to as “sender” and “reader”
4) NFS mounting the spool is not an option.
5) Using fetchmail is not an option.
6) Using only one machine to accomplish both tasks is not an option.
7) Any/all databases must be maintained automatically, rebuilding every 10 minutes.
8) Inbound mail to first.last must be delivered, but reader cannot have an aliases file.
9) Mail cannot be sent locally on reader, but must first go to sender to have addresses rewritten.
10) All Majordomo aliases, and the program itself must live on sender.
11) Special exception aliases must work correctly, even if they are amalgams of the first.last pair.
sendmail  mailserver  sysadmin 
march 2018 by dusko
mail-tester.com -- newsletters spam test
Check your newsletter's spam score and quality. This tool's free, and pretty.
mail  sysadmin  mailserver  smtp  email 
january 2018 by dusko
logwatch -- what's a -bs?
> what's a -bs?

A sendmail commandline parameter used by programs like pine to send mail. If the sender is not a trusted user this warning is written to the logs.
smtp  log  mailserver  server  sysadmin  sendmail 
december 2017 by dusko
mb2md.pl
Mbox to Maildir conversion (forked from version on dovecot.org)

Updated to add a '-v' option that will strip a directory extension (much like '-r' would strip an mbox extension.
email  mailserver  sysadmin  perl 
december 2017 by dusko
Postmaster info - AOL
Information on methods and support for issues concerning mail
mailserver  sysadmin 
august 2017 by dusko
Your Idea to Fighting Spam Will Not Work
Your post advocates a

( ) technical ( ) legislative ( ) market-based ( ) vigilante

approach to fighting spam. Your idea will not work. Here is why it won't work. (One or more of the following may apply to your particular idea, and it may have other flaws which used to vary from state to state before a bad federal law was passed.)
spam  sysadmin  mailserver  email  devops 
december 2016 by dusko
E-mail move today
key word "move", not migration. Some of these people have had the same e-mail for 10+ years, no restrictions or anything. Switching to corporate's e-mail with all kinds of restrictions, including email retention rates. -- What sort of fun are you guys having today? ---- We did that 7 years ago. It was a fucking month of a trail of tears and sob stories about lost emails, then another solid two years of complaints about the retention policies. -- Stock up on booze. -- Today, and the next two weeks are "read only" for us. We're about to open a big new branch office mid-June, and this week is the calm before the storm. My people have been instructed that changes result in termination AND crucifixions, our job is just to get the helpdesk queue to zero and keep it there. --- Posted on Mar 23, 2016.
sysadmin  mail  mailserver  email 
may 2016 by dusko
Get Help Upgrading Zimbra Collaboration, free online training course
Need help upgrading Zimbra Collaboration 7.x to the latest release? Watch this free online training course (http://info.zimbra.com/how-to-upgrade-to-zimbra-collaboration-8-training-video) and learn about: * New features for IT such as rolling upgrades and auto provisioning, * User enhancements including new clients and accessibility support for mail, * How to upgrade Zimbra Collaboration using a rolling upgrade process, * Other upgrade methods including Rsync and full migration. ==== Watch the on-demand training video now (http://info.zimbra.com/how-to-upgrade-to-zimbra-collaboration-8-training-video) for help upgrading from Zimbra Collaboration 7.x to Zimbra Collaboration 8.x. ==== Posted on May 19, 2015.
mail  sysadmin  zimbra  mailserver  smtp  email 
november 2015 by dusko
Debian Mail Server - Part 2: SPF and DKIM
TL;DR: check mail-tester.com (https://www.mail-tester.com/). If you don't get 10/10, read this post.
mailserver  smtp  email  sysadmin 
november 2015 by dusko
Listing Distribution List Members - Zimbra
We have been using the distribution lists feature via the Admin UI for a while now, and we keep finding more and more uses for them. The only problem that we have come across (caused by us) is that we need to periodically audit the members of each distribution list. We do this to make sure that all required users are on each list, and that no one is on a list that they shouldn't be. ==== I did not see anything already available that did this so I put together a real basic LDAP query to accomplish this task. I figured that if I needed to do this someone else would also, so here is the basic query to list the members of all distribution lists.
LDAP  mail  sysadmin  zimbra  mailserver  email 
october 2015 by dusko
Mailboxes by Distribution List - Zimbra
One of our domains has about 100 distribution lists for each of their departments/offices, and requested a way to get a breakdown of all of their users, and which distribution lists they were in. ---- I saved this file in /opt/zimbra/backup/scripts/ as userbreakdown.sh, owned by zimbra.zimbra chmod 755 userbreakdown.sh
mail  sysadmin  zimbra  mailserver  email 
october 2015 by dusko
Announcement: Zimbra Higher-Ed Admins mailing list
For those of you who manage Zimbra for a post-secondary institution, you know there are 'special' challenges associated with running such a sophisticated piece of software on such a large scale. ==== Last month, I launched a mailing list allowing us to discuss such challenges and share our solutions. Now that Zimbra has an Edu forum, I have a place to announce it here as well. ==== Discussion could range from hardware architecture, to user documentation, to collaborating on Zimlets (I hope :) ), and everything in between. ==== To subscribe, send a message to zimbra-hied-admins-request@sfu.ca with the word "subscribe" in the Subject line. There's an archive of postings to date (pretty light so far) here: zimbra-hied-admins list (http://www.sfu.ca/~hillman/zimbra-hied-admins) by thread ==== Thanks! - Steve Hillman - IT Architect - Simon Fraser University ==== Posted: Apr 14, 2008.
mail  sysadmin  zimbra  mailserver  email 
august 2015 by dusko
Script for Export-Import Zimbra Mail Server Accounts and Passwords
Script for Export-Import Zimbra Mail Server Accounts and Passwords
mail  sysadmin  zimbra  mailserver  email 
august 2015 by dusko
SSL Cert requests should use SHA 256 signatures - Zimbra 8.5 - New Features ZCS 8.5
## SSL Cert requests should use SHA 256 signatures ##

Reference:
https://bugzilla.zimbra.com/show_bug.cgi?id=86761

To enhance security, the default signature of cert requests is now 256 bits.
mail  sysadmin  zimbra  mailserver  email 
june 2015 by dusko
Zimbra 8.5 - New Features ZCS 8.5
Bringing to notice some notable new features and functionality released with ZCS 8.5.
mail  sysadmin  zimbra  mailserver  email 
june 2015 by dusko
Zimbra: Activar HTTP Strict Transport Layer y conseguir el A+ en el test de SSL Labs
Zimbra: Enable HTTP Strict Transport Layer and get the A + on the test of SSL Labs --- Posted: Jun 18, 2015.
mail  sysadmin  zimbra  mailserver  email 
june 2015 by dusko
Zimbra: Enable HTTP Strict Transport Layer and get the A + on the test of SSL Labs (Google Translate)
Zimbra: Enable HTTP Strict Transport Layer and get the A + on the test of SSL Labs --- Posted: Jun 18, 2015.
mail  sysadmin  zimbra  mailserver  email 
june 2015 by dusko
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