The drawer has three years to draw it to your attention under 4-111. As JacFSB notes, the paying bank has the same time frame to go back to any bank that passed it to you and provided warranties. We're both quoting from the model language, look at the parallel provisions in your state - they may differ.
While some portions of the UCC can be limited by agreement, you cannot impose on the drawer a duty to detect a forged endorsement; your signature card cannot shorten this statutory time frame. The law assumes that the drawer is incapable of recognizing a forged endorsement. If you send images of only the front of the item you made it impossible for him to do so.
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In this world you must be oh so smart or oh so pleasant. Well, for years I was smart. I recommend pleasant.