According to https://help.salesforce.com/articleView?id=000321158&type=1&language=en_US&mode=1, Salesforce supports comments in email addresses
Comments – denoted by matched parentheses – are allowed in the domain
as well as in the local-part. Comments in an email address are ignored
when sending email; for example, john.doe@(comment)example.com, and
email@example.com(comment) are both equivalent to
This does not seem to be the case as this procedure can be seen failing with the error “You have entered an invalid format.” on the following screenshot(here I am assigning this email address to a Contact):
This example was copy-pasted straight from the Salesforce help article, so it should be sufficient to demonstrate the inoperability of this functionality. I also tested placing comments before the @ and after the @ and before the domain name — all options failed.
I understand that this functionality is quite niche and largely more weird and unintuitive than helpful, however I believe it would help me solve an on-going production issue, so I’m a bit baffled as to how this RFC approved format seems to not be accepted in this field.