Allow plus addressing in Multi Inbox

[BetaLyte]

What's your idea? Go! Functionality of Multi Inboxes can be extended by allowing the use of plus addressing. Services and users can then use a plus address, instead of a separate inbox with redirect, to apply a template automatically at creation time.

Additional context The regex in the MultipleMailboxes form just needs to accept an optional +whatever, ie. ^([0-9a-zA-Z]([-.\w]*[0-9a-zA-Z])*(\+[0-9a-zA-Z]([-.\w]*[0-9a-zA-Z]))*@([0-9a-zA-Z][-\w]*[0-9a-zA-Z]\.)+[a-zA-Z]{2,9})$

[AdhocAdam]

I had to read this a couple of times, but I think I'm following now. Initially it sounded like wholly new functionality for Multi-Mailbox, when in fact it's more of an enhancement as you're suggesting loosening the restriction on the textbox validation. In that you could use a "+" in an email address. Such as:

• mail@lab.lcl
• mail+@lab.lcl
• mail+incident@lab.lcl

Am I getting that right?

[BetaLyte]

Re-reading what I wrote, I can see that it's explained just a bit convoluted.

Yes, I'm proposing changing the validation on the email field of Multi-Mailbox, so that it's possible to use plus-addressing, such as your examples (apart from nr. 2, that shouldn't be a valid email address).

We are already using it in our own env, and it's a lot easier, than creating additional mailboxes, just for the sake of redirecting the mails to apply templates.

[AdhocAdam]

I created a mailbox in Exchange and the second example above is allowed. But given the purpose of the issue/PR you've raised, this is probably extraordinarily edge case. Just wanted to put this here for the sake of documentation.

Otherwise, I tested this build out and looks like all is well for multi-mailbox configuration options. Current functionality is preserved and extended per your pull request. Second mailbox scenario is prevented within the Settings UI. 👍

This will be included with the next release 😄

[AdhocAdam]

Will ship via #468