I just checked and simplemail uses amissl v1. The library file is named amissl.library
While amissl v3 (used by ibrowse afair) is amisslmaster.library

Again, it's like foo.so.1 versus foo.so.3 on unix... similar names but completly different libraries/projects/apis. Other (all of them?) amiga shared libraries don't work this way and expand on the existing. Always keeping ascending compatibility.
Yes it's a mess... thank you unix ;-)