I agree with the answers so far.
Typically when a buyer's agent emails an offer to the listing Realtor a "received" reply email is sent to confirm receipt of the offer.
From my experience virtually every property in Tampa Bay (other than those above $250k or significantly overpriced) will get multiple offers and your agent will be notified of a deadline to submit your "highest and best" offer. After that it normally takes no more than 48 hours to get a notification if you were the "winner" or the "loser".
In some cases you may get a counteroffer (this is especially true on less desirable or overpriced listings) and you can then accept, reject or counter. If you counter you could end up in a multiple offer scenario if another offer comes in before your counter is accepted or countered.
Even on Fannie Mae properties where the buyer's agent inputs the offer online, I think the listing Realtor has to review them before they get transmitted to the asset manager that makes the decision to either accept or counter.
There are some great websites where REOs auction properties online and it is 100% transparent and you can even see your bid and increase your bid before the deadline if needed. I wish they were all done this way.
Hope this helps.
All the best,
Alma Rose Kee, PA
Future Home Realty