Mail Solutions

Reasons for a mail server: 

  1. One of the main reasons companies opt for a mail server is one of control. With a dedicated mail server the client can monitor and control who is sending/receiving what?
  2. Another reason is that when having more than a couple of users on a LAN, mail sent to one another without a mail server is sent over the internet and then received over the internet even though the person you are sending to is sitting right next to you. This alleviates bandwidth.
  3. Mail servers alleviate the internet speed as email isn't sent back and fourth over the lines, because all mail on the same domains (eg computaweb.co.za) stays local.
  4. Lastly, some companies want to keep a copy of all correspondence sent and received by everyone in the company incase of complications that may arise for disputes with clients.   

Control and security: 

  • With our mail solution you will be able to block file types,  control spam and malware with quarantining functionality.
  • Message content filtering via file extension, file type, file name, and size etc.
  • Web-based interface displays mail reports.
  • Quarantine features of undesirable mails.
  • Release wrongly quarantined mails via web interface.

 What we use for Virus and Spam Filtering:

  • Clam AntiVirus is an open source (GPL) anti-virus toolkit for UNIX, designed especially for e-mail scanning on mail gateways
  • Virus scanning on incoming and outgoing email with unlimited updates.(no yearly renewals)
  • Spam filtering is done via Spam assassin.
  • Spam scans tests are conducted via subject, body, and many other misc tests.                                             
Features:
  • Pop/SMTP/IMAP
  • Capable of processing thousands of mails per hour.
  • Add disclaimers to all outgoing mail.
  • Webmail for clients that want to check mail without having there PC on, eg going overseas or at an internet cafe
  • Mail archiving of all mail. Keeping a copy of all mail sent and received
                                 
Example configurations
 
Scenario 1.
A client wants a mail server at each branch so as to alleviate the lines a bit as there are 70 users at each branch. The client has one mailserver at head office which recieves all mail for that domain on the internet. Each branch has its own mail server. Each branch is connected via diginet to the main head office.
Head office mail server downloads all mail for the domain. the branch mail servers download mail from the main headoffice server. All mail at the branches to each other stays local, if a user wants to send to another branch, postfix checks the local user database, if that user doesn't exist on the local mail server, it forwards to the main server and the relevant branch fetchs it from there. ALl of this is done transparently to the user.
  
Scenario 2.
A Client wants to control all mail sent and received from their branches connected to their VPN. We install postfix on the vpn server and set everyones smtp to be the address of the postfix server. We then create a list of authorised users and authorised email addresses and configure postfix to integrate these lists. If the sending user is on that authorized list, he/she can send to whomever he/she wants to. If that person isn't on the authorized list, they will only be able to send to the emails on the authorised email list. all other mail will be returned with an error.