There are various reasons you may need to switch hosting companies: your company goes out of business, you need services your current host doesn't offer, etc. Moving your website from one hosting company to another is, generally, pretty easy. However, moving your email services to another company can be a bit more labor intensive. Below are a few ways you can move your SmarterMail email from one hosting company to another.
The first thing to consider is whether your new provider offers SmarterMail or not. If they don't then you'll need to migrate your email account rather than simply moving it. Migration of emails, calendar appointments, contacts, etc. can be a time consuming, and really depends on the service you're moving to. However, a SmarterMail-to-SmarterMail move is really pretty easy.
Moving From SmarterMail to SmarterMail
The simplest thing to do is simply move your SmarterMail domain from one instance of SmarterMail to another. This entails getting your Domain folder from your current provider, and giving it to your new host. The new host can then attach or import your domain to their SmarterMail installation, and that's about it. From there, DNS changes will need to be made.
In order to preserve emails, you can do a few things:
1. Have your current provider disable your domain before giving you the domains folder. This will mean email will be attempt to be delivered to accounts, but it won't be. This would prevent the loss of email, especially for users who solely use the webmail interface. The messages will remain "active", or there will be multiple delivery attempts, before the messages are returned to the sender. Of course, the timing of those attempts, and the total number of attempts, is dependent on the sending server. Regardless, it should give you time to move your domain to a new provider, make necessary DNS changes, and get the domain active again at the new host.
2. Have users attach their accounts using an email client, like eM Client or Outlook. This way, they'll continue to receive emails during the transition. The only impact would be DNS changes necessary when moving hosts. However, that shouldn't impact the delivery or receipt of email much, if at all.
3. Time the move to occur when there's the least possible chance messages will be lost. This could be in the evening, on the weekend, or even during a holiday. Your provider(s) should continue offering support for the move, but your users will see the least amount of impact.
4. A combination of all of these.
Migrating From SmarterMail to SmarterMail
If your existing hosting provider won't give you your domains folder, there is still something you can do: simply migrate from your old provider to your new one. Using Mailbox Migration you can move your email, calendars, contacts, tasks, and notes from your old SmarterMail host to your new one.
NOTE: The source SmarterMail server needs to have MAPI/EWS enabled for accounts in order to pull over Calendars, Contacts, Notes, and Tasks. Otherwise, the connection will default to IMAP and only email will be transferred.
New accounts will need to be set up at the new hosting provider, then each user can go to Settings > Connectivity and use Mailbox Migration to retrieve their information. You would simply need to provide them with the necessary connection information (I.e., Server Address) of the previous provider. Mailbox Migration between SmarterMail servers is quick, and extremely efficient.
Migrating From SmarterMail to Another Email Service
Of course, moving from one SmarterMail provider to another is the simplest, and best, way to preserve your email and all other account information. However, there may be the need to migrate from SmarterMail to another email provider. If this is the case, the new service should provide a way to move at least email data over. Usually, this is handled via an IMAP migration. Some may offer a way to migrate using POP, but if IMAP is an option, you'll want to use that.
There are limitations to IMAP migrations, and those revolve around what can be migrated: generally, it's just email messages. Things like calendars, contacts, tasks, and notes cannot be migrated in this way. If the new service provider offers EAS or EWS, these can generally handle email, calendars, etc. If WebDAV is an option, that, combined with IMAP, can bring email as well as calendars and/or contacts over.
Prior to any move, we strongly recommend you check with your new service provider and get ALL of your options for moving or migrating your email. It's easy to move website files and, usually, your website can withstand an hour or more of downtime. However, email is so crucial, minutes matter. So, get your options and make a plan before initiating any changes when moving your email service.