[suggestion] make encoder/decoder configurable to avoid conflicts with eiconv

[fcevado]

When using a different encoding/decoding library than eiconv i need to make a fake module that implements the convert/3. if a dependency uses eiconv, it might lead co conflicts.

my suggestion is to have it being configurable, so gen_smtp uses the configured module, otherwise keep using eiconv.
for the sake of documenting it would be good to have a behaviour defining a contract for convert/3.

[Vagabond]

That should be relatively easy to do. You could just add a new option key to mimemail's options tuple and thread it through to where it calls mimemail:convert/3

[fcevado]

yep, i'm planning to work on this this weekend, just asking if the approach is approved. should i include the behavior? probably mimemail_encoder or something like that

[Vagabond]

I am not super concerned about the behaviour, if someone configures a module that doesn't work it can just crash, or you can use module:is_exported. Using a behaviour would introduce an annoying dependency, I think?