Please provide a way to make "IMAP vs POP3 as the default" configurable for preseeding

Please provide a way to make "IMAP vs POP3 as the default" configurable when creating a new account. This would be useful for Tails who would like to make it possible to, for example

default to POP3 if persistence is enabled
default to IMAP if persistence is not enabled

Changing the default currently requires modifying the Torbirdy source.

Trac:
Username: kytv

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