Sharp MX-3610N User Manual page 529

In the following situations, the transmission will be automatically reserved (memory
transmission)
When the line is busy or a communication error occurs and automatic resending
is enabled.
WHEN A COMMUNICATION ERROR OCCURS
The line of the machine will be busy if another fax is being sent, received, or if
the machine is in the busy state.
Another fax transmission was reserved ahead of your fax.
One of the following functions is being used for transmission.
Broadcast transmission, F-code transmission, Timer transmission, Dual Page
Scan, Book Divide, 2in1, Card Shot, Job Build, Original Count
The document glass is being used (except when the speaker is being used to
dial).
To disable the Quick On Line Sending setting:
In "Setting mode", select [System Settings] → [Image Send Settings] → [Fax
Settings] → [Send Settings] → [Quick On Line Sending].
If you disable this setting, transmission will not begin until all pages have been
scanned. Note that this setting does not apply to manual transmission.
To fax thick originals or pages of a book:
Place the original on the document glass.
USING THE DOCUMENT GLASS FOR
TRANSMISSION
Quick On Line Sending is not available when a fax is being sent from the
document glass.
When the document glass is used, multiple original pages cannot be scanned at
a time. In this case, the original pages can be separated into multiple times of
scanning.
If you wish to send a fax ahead of other previously reserved
fax transmissions:
Send the fax in direct transmission mode.
The original is transmitted directly to the
receiving fax machine without being scanned