RI 2530 fax issue only on E fax -some parameter setting???

[Sam Tofu]

Don't work on many of these. Customer says fax OK in/out on regular. Has many E fax customers he sends to all the time on the RI 2530. Yesterday all of a sudden (regular faxing OK) E fax wouldn't go through on any. He was able to send the E fax by a back up fax.

Seems it is probably some parameter setting? But not certain what to look for on this. Have basic manual and parts and have fax manual for the 3035 series.

Any tips or awareness of settings on this much appreciated!

thanks in advance