You can add this configuration with: "more | envelope | add config for an application". 
-- begin Envelope config --

[Eudora Pro]
# tested on version 3.05 and 4.0
# beeps in the out-box
# 980320
windowtitle=eudora pro
header1=+{tab}%o^a^c
header2=%c^c
header3=%b^c^{home}{tab}{tab}
copy=^a^c^{home}
paste=^a^v^c^{home}
check1=^r^a^v^c^{home}
check2=%ms^a^v^c^{home}

-- end Envelope config --