Email validation issues

[iptelephony]

Information about bug

The current email validation logic fails with certain RFC-5322 compliant addresses.

E.g.

"John, Doe" [email protected]

It fails at 3 levels:

1. Email address validation regular expression does not account for comma in display name
2. Email address splitting also fails to account for commas enclosed in quotes
3. The frappe API for sending email also does not account for commas in display names.

Version

Frappe version: 15.68.0
Helpdesk version: 1.7.0

Installation method

None

Relevant log output / Stack trace / Full Error Message.