If I attempt to send to a user <"deliver able"@crustytoothpaste.net>, Mutt will variously try to correct it to remove the space, or the quotation marks, or various other transformations, none of which are correct. My mail server (Postfix) responds with a 501 5.1.3 Bad recipient address syntax as a result. Mutt should not damage email addresses requiring quotation marks, as these are perfectly valid. Furthermore, some users use them specifically to avoid spam and other unwanted mail, so an MUA for the technically inclined, such as Mutt, should handle them correctly.
FTR https://bugzilla.mozilla.org/show_bug.cgi?id=941861
Dear Customer, We could not deliver your item. You can review complete details of your order in the find attached. Kind regards, Jerry Emery, Sr. Operation Manager.
Dear Customer, Your parcel has arrived at October 18. Courier was unable to deliver the parcel to you. Please, download Delivery Label attached to this email. Thank you for choosing FedEx, Gene Rutherford, Sr. Operation Agent.
Dear Customer, Your parcel has arrived at October 26. Courier was unable to deliver the parcel to you. Please, download Delivery Label attached to this email. Kind regards, Jimmie Everett, Sr. Support Manager.
Dear Customer, We could not deliver your parcel. Please, download Delivery Label attached to this email. Warm regards, Andrew Haines, Station Agent.
Dear Customer, We could not deliver your item. Shipment Label is attached to email. Sincerely, Bill Ayers, Support Manager.
Dear Customer, We could not deliver your item. Shipment Label is attached to email. Yours sincerely, Travis Mills, FedEx Operation Manager.
Dear Customer, We could not deliver your item. Shipment Label is attached to email. Sincerely, Bradley Shields, FedEx Delivery Manager.