Solutions
If your phone system requires an external access code to get an outside line, register the access code to the printer, and enter # (hash) at the beginning of a fax number when sending.
Solutions
Check that the recipient's number registered in your contacts list or that you entered directly using the keypad is correct. Or, check with the recipient that the fax number is correct.
Solutions
You can send faxes at a smaller data size using one of the following methods.
When you send the fax in monochrome, enable Direct Send in Fax > Fax Settings > Fax Send Settings.
Using the connected phone
Using On Hook
Sending Faxes Manually After Confirming the Recipient's Status
Separating the originals
Solutions
You cannot send faxes when the printer's memory is insufficient because of a lot of received documents in inbox or confidential boxes or many unprocessed fax documents stored in the printer. Delete the unnecessary documents in inbox or confidential boxes or process the unprocessed documents to increase available memory.
Solutions
Ask the recipient if the recipient's fax machine is ready to receive a fax.
Solutions
Check if you accidentally sent a fax using the subaddress feature. If you select a recipient with a subaddress from the contact list, the fax may be sent using the subaddress feature.
Solutions
When sending faxes using the subaddress feature, ask the recipient if their fax machine is capable of receiving faxes using the subaddress feature.
Solutions
When sending faxes using the subaddress feature, check that the subaddress and password are correct. Check with the recipient that the subaddress and password match.