I might just be using the wrong keywords on Google, but what I have in mind is:
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| What is your mailbox? |
| |
| [ ]@mail.example.org |
| |
| [OK] [Cancel] |
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The idea being that the input field is followed right behind by the mail server name, to help avoid instances where:
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If I don’t make it follow right behind, the user puts in the whole thing,
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If I default it to “blah@mail.example.org” they delete the server name.
In either case, it’s not too big a deal, as I will know that if the returned value does have the server, to remove it and if doesn’t, I know what server it belongs to, but I think this visual aid will be a better user experience and lower the amount of validation worries I tend to get.
You can set a default value in the standard Javascript prompts, but you can’t do much more than that. I would just check afterwards and strip or add the server part as needed.