diff --git a/frappe/core/doctype/communication/communication.py b/frappe/core/doctype/communication/communication.py
index 28ca7abf4f..9e6907edd6 100644
--- a/frappe/core/doctype/communication/communication.py
+++ b/frappe/core/doctype/communication/communication.py
@@ -401,7 +401,11 @@ class Communication(Document, CommunicationEmailMixin):
 			return
 
 		for doctype, docname in parse_email([self.recipients, self.cc, self.bcc]):
-			if not frappe.db.get_value(doctype, docname, ignore=True):
+			# Both document and doctype names should be case insensitive in email addresses.
+			doctype = frappe.db.get_value("DocType", doctype)
+			if doctype:
+				docname = frappe.db.get_value(doctype, docname, ignore=True)
+			if not (doctype and docname):
 				continue
 
 			self.add_link(doctype, docname)