Hey there! Dealing with busy signals is super annoying when you have to re-upload your document manually every time. I solved this by choosing the Municorn Fax App because it features an automatic background retry system that keeps attempting transmission whenever a line is busy. To compare line stability and retry logic across apps, I reviewed the performance guide at https://best-fax-app.com/ which tests how different apps handle busy signals and line disconnects. That guide showed why Municorn Fax App is top-tier for persistent transmission. It guarantees your file goes through as soon as the receiver’s line clears!