Email: External Verses Internal Hosting

Hello again and welcome to a somewhat different blog post.
This time, I’ve been asked to come up with a less instructional, and more theoretical blog post. I have decided to make it all about the two main ways to run an email server, internally and hosted.
Finally, a few caveats:

  • Your mileage may vary. I have tried to compare these points in a neutral as way as possible, however you may find that you want to give the redundancy bonuses a higher weight in discussions and so it may alter the points I raise.
  • Secondly, These are my opinions that I have formed from my experiences and learning and may not necessarily represent the views of either Amsys or other Amsys employees.


Having your email server both owned, run by, and operated from your company tends to be the go-to for almost all small to medium businesses. In this area, your choice of email server largely comes down to what OS your server will run.
If you elect to run a Microsoft Windows server, the most popular (and best integrated mail server) would be a Microsoft Exchange server. As with most mail servers in this blog, Exchange provides not just email services but Calendar and Contact services too. Exchange’s strength is in its ability to provide a hugely scalable solution, allowing the potential solution to grow with your business but at a cost.

microsoft exchange server

If you decide on an Apple Server, you will gain a fully-fledged (although problematic) mail server with the server OS. Alternatively you can run with a number of third party mail servers such as Kerio Connect, a cheap yet reliable mail server, just lacking in an easily scalable solution.

kerio connect

If you decide on a more open source server box, than there are countless possibilities of email solution, but with the increased demand of more highly trained support staff to configure and support the solution.


There are a large number of external email hosts, right from those you can get free with your domain, up to worldwide international providers. In recent years, these international providers have increased their uptime SLAs and decreased their prices to make them extremely competitive with the cheaper (and less feature-filled) solutions.
In this section I will be concentrating on the big two, Google and Microsoft. Both of these computing giants provided SLA’d uptime of 99.9% with data redundancy spread not just over multiple servers (and multiple server farms) but also across location around the world. They both provide the ability to act as mail servers as well as calendar and contact servers.

microsoft office 365

Microsoft provides a cheap but fully-fledged version of their Exchange server solution called Office 365. Microsoft provides the back end configuration, update management and support, allowing you and your company to worry about just the user’s email addresses and distribution groups. As it is a standard Exchange solution, it is compatible with almost every email client out there, and for those that won’t run Exchange; it supports IMAP and POP connections too.
Google’s offering ticks many of the same boxes, but is provided through their own bespoke mail server solution. Email is provided primarily though a web page (something that is not preferred by some companies) with IMAP and POP connections also possible. As with Exchange, Google look after all of the back end equipment and support allowing you to concentrate just on the configuration specific to your environment.


So now you have a fair idea of the differing choices in what you can use to host your email, split into internally hosted servers and external ‘software as a service’ hosted servers. But how do you make that decision in the first place?
In this section, I’ve gone through some of the most common pros and cons of each side to help you make a decision.

Internally Hosted email provides you with more control.

To both own and run your own email servers allows you a greater control and freedom over your own solution. If you want to give Joe Blogs an extra 25 GB storage on his mailbox, go for it. You might need to purchase extra storage for the server but it is much simpler to carry out.

Internally hosted email is cheaper.

Unfortunately this is no longer the case, or at least its no longer as cut and dry. A perfect example is a solution I recently configured for a client. 18 users, 25 GB mailbox storage limit per user, a few alias’ and distribution groups and shared contacts and calendars. Full price of the entire solution: £70 (plus VAT) a month, and that’s including maintenance and failure management. No start up cost (other then myself to run through the configuration). This is a price that is struggling to compete with an in house mail server solution, where the server its self can cost £400-500. On top of the monthly cost of an IT staff member to maintain and manage any failures with the server.

Externally hosted email offers better redundancy and up-time

Imagine this, you host your own internal email server. The server has an issue and needs to be taken offline. This would leave you without email for the entire period.
Now you buy a second email server, with full replication to ensure that if one server needs to be taken down, you’re not without email. This has cost you around twice the cost (for a second identical server) plus a higher support contract to configure and support a more complex solution. This time, your Internet goes down and once again you a left without email for the entire time.
Now you also buy and install a second telephone line, with a second Internet connection and have a full data fail-over solution configured. Again, this will raise the cost of your support contract, or you end up employing a dedicated IT person to support the entire solution, plus you have paid for some sort of cover for holiday or sickness. This time the power in the building goes out, again leaving you with no email for the entire time.
For almost all small businesses, to protect against all of these events would raise their IT costs to a level they cannot afford. But to lose your email server for 24 hours often cripples a small business beyond a point that they can recover from.
With hosted email (dependent on who you go with), they provide world-class facilities to hundreds, perhaps thousands of businesses and so can afford not only multiple servers or server farms, but also multiple Internet connections, back up power generators and multiple locations all over the world. These measures, although costly, are affordable for the number of clients they support and so the benefits can be shared at minimal cost.

Internal hosted email provides a better guarantee of data protection

There are a number of smaller businesses out there whose data cannot be stored on, for example, American servers due to data protection. As the major and arguably best hosting companies have servers in the United States, this could cause problems with government access to the data. The safest option to guarantee that your data stays outside of the USA is to host your own email server/s.
Anybody who may be affected by this will find some helpful information here >>


There you have it. I’ve tried to keep things as low on the technical side but high on the theoretical side (with some real world examples) regarding where to have your email hosted. If you feel I have given you a lot more to think about; I’m happy because these are concerns that all companies using email should have (amongst others). If you feel I’ve just complicated and confused matters for you, I can only apologise and ask that you raise your issues in the comments and I’ll do my best to answer them.
As always, if you have any questions, queries or comments, let us know below and I’ll try to respond to and delve into as many as I can.