Generally email is a bit like the web space issue. You usually get more than you need. The one case however where it can be an issue is in choosing between the two lower cost plans.
The Starter Plan provides a single mailbox whereas the Business Plan provides ten mailboxes. In both cases each mailbox can have unlimited aliases. If you know what this means skip the next paragraph or so but if not read on!
A mailbox is a location where email arrives, a bit like a real mailing address. So a mailbox of firstname.lastname@example.org is a bit like, say, 99 Your Road, Your Town, Your Code would be where posted mail is concerned.
That mailbox can have several aliases. For example "fredsmith" might be an alias for "mail" and so anything sent to email@example.com would end up in the mailbox called firstname.lastname@example.org just as a letter sent to Mr Fred Smith, 99 Your Road, YourTown, etc would physically be put into the same mailbox as a letter sent to The Occupier, 99 Your Road, etc.
The letters all land on the same doormat, you can see who they are for and you may choose not to open Fred's letters for him but there is no real security between the different aliases. You can set up as many "fredsmith@" aliases to a single "mail@" mailbox as you like and for a family or even small business web site that is just fine.
However if you require some privacy you need more mailboxes. Imagine you are a small business, you might not want the employees to see emails sent to the boss! It might be irritating for the technical department to sift through the hundreds of emailed sales enquiries generated by your wonderful web site to find the three a day sent to them. So give them each seperate mailboxes, sales@, technical@, boss@, whatever you like. They can still have multiple aliases per mailbox so charlie@, sidney@ and mabel@ can all end up in the same sales@ mailbox but each function can be kept seperate as far as you wish.
Each web hosting plan clearly states the number of mailboxes included, each mailbox can have as many aliases as you like and the whole thing is set up, without any need for technical expertise, through a special web page we give you called the control panel.
And if you are unsure - contact us.