Originally Posted by Doitsu
Since most eReaders manufacturers have licensed the mobile edition of Adobe Digital Editions, I'd recommend installing Wine and Adobe Digital Editions to test your ePub with it. (AFAIK, this can be a bit tricky, but it can be done.)
If your embedded font doesn't show up correctly in ADE, it won't show up correctly on most eReaders either. Assuming that your stylesheet is indeed coded correctly, it also means that your font cannot be embedded, even if it shows up correctly in Sigil, because ADE is way more picky than Sigil.
If it works with ADE, your ePub should theoretically work on all officially supported ADE devices and apps
Thanks for your great help Doitsu, Let me install and check whether my font embedding works properly or not. Thanks for your time.