I too am having the same issue as of last night. I have reconfirmed all the settings in the smtp screen. I get the activation email OK, but when emailing invoices I get the same error: (Clutter is disabled on my account)
We have been unable to send a number of items through your own custom SMTP email server. The last 3 consecutive attempts failed. The error recorded is as follows:
Email: firstname.lastname@example.org Error: Transaction failed. The server response was: 5.2.0 STOREDRV.Submission.Exception:SendAsDeniedException.MapiExceptionSendAsDenied; Failed to process message due to a permanent exception with message Cannot submit message. 16.55847:60180000, 17.43559:000000009C000000000000000000000000000000, 20.52176:140F3B850000101040000830, 20.50032:140F3B85701710100A000B30, 0.35180:41040000, 255.23226:0A001D30, 255.27962:7A000000, 255.27962:0A000000, 255.27962:0E000000, 255.31418:80030400, 16.55847:B6000000, 17.43559:0000000068010000000000000200000000000000, 20.52176:140F3B85000010100A002381, 20.50032:140F3B85701710100201FE67, 0.35180:64040000, 255.23226:0B004536, 255.27962:0A000000, 255.27962:32000000, 255.17082:DC040000, 0.27745:1F001A00, 4.21921:DC040000, 255.27962:FA000000, 255.1494:9F040000, 0.37692:0F010480, 0.37948:26B0701E, 5.33852:00000000534D545000000000, 4.56248:DC040000, 7.40748:01000000005E08AA30303A41, 7.57132:00000000000000003A666439, 1.63016:32000000, 4.39640:DC040000, 8.45434:E2B013CF1253614D85CDB6F9F8B65EB151D29443, 5.10786:0000000031352E32302E3133…
Please return to the SMTP settings page on your QuickFile account (Account Settings Area). If you have recently changed your email password or any other credentials please update and reactivate your SMTP services accordingly.