We recently switched our mail provider at work from Messagelabs to MimeCast. We had been using Messagelabs for several years with no real problems. Messagelabs offer an Anti Spam and Anti Virus email scanner and then delivers mail to your mail gateway, they stated in our contract that it would protect our system 100%, however they did actually let one virus through, thankfully we had MailSweeper which caught it. The increase of menacing bugs and threats that wonder the World Wide Web means that security services forever have to change and evolve too, always adjusting to the capability of the bugs. Even mobile phones with broadband are not safe. Like O2 phones that are equipped with the latest functions that enable people to send texts, surf the web, capture images, tune into music and check their email. It will not take long till a Virus creator can completely shut mobile phones down. However with speedy upgrades of handsets just now every unit should be able to counter the viruses with security systems and mailsweepers.
Any way our setup was very much like the picture below:
Our MX records were pointing to the Messagelabs towers, it then delivered the emails to our MailSweeper Server, which then delivered to Exchange. We have journalling enabled so as soon as the email was delivered to Exchange it was also dropped into the CryoServer mailbox, which then keeps a copy of the email indefinitely.
We have never had a problem with MailSweeper and it always gave us piece of mind as it sat in the DMZ and screened all emails in and out of the company.
February this year we decided to switch over from Messagelabs, not that it had been a bad service, far from it we were happy with the service, but because they only offered the same service as they had always offered us. MimeCast however offered three services in one package (Anti Virus and Anti Spam, Archiving, and File Type Blocking), MimeCast Multi. It also offered us a BCM (Business Contingency Managment) Solution.
The beauty of this product meant that we could cut costs and save some money on maintenance, support and means everything is in the one place.
So the setup we have now is like this picture below:
We had to open our firewall to talk to MimeCast direct from our Exchange Servers on port 25 (smtp) For Exchange and Port 110 (pop) for the journalling option, and we also needed to open up port 389 (LDAP) so that the MimeCast Towers could talk to our Domain Controller so we could enable our users to log on to the MimeCast if they ever needed to due to exchange being down.
One of the other features that made us decide to switch to MimeCast was the ability to be able to log on to the MimeCast Towers using a web browser.
The first part of the switch over was for changing our outgoing email Internet connection to deliver via MimeCast and not MailSweeper and Messagelabs. We let that run for several weeks and then changed our MX records to point to MimeCast instead of Messagelabs.
We have been using MimeCast for 2 weeks with email going and and out through it and we have so far had no problems with the service.