This is really not recommended, at least even if it is hardcoded it should be capitalized first letter to make it easier to recognize it as the name/value of a field, lower case like that will easily be mistaken for item/field type.
I appreciate your help, but this is generally a pain.
If possible, I hope you can submit a pull request that modifies the PP importer source code:
- Change the custom field name from
email
toEmail
as I explained the reason above. - Add PP’s handling of
alias
type as in my reply #4.
This should solve this problem once and for all.