I had a a list of emails that I blocked as spam. Recently I decided to clear the list. All the email addresses were deleted except for one: oqazv7lqse22ul/9fwbd/g==_1131635298216_sjodpoefeemvkdsuupqfdq==@in.constantcontact.com

When I try to delete it I receive a message "zoho\x2Dinputstream\x20Input\x20does\x20not\x20match\x20the\x20given\x20pattern"

Please help.