COPY vs APPEND for imapsieve?

[MRob]

On 2016-12-05 06:16, Stephan Bosch wrote:
> Op 5-12-2016 om 14:36 schreef MRob:
>> The examples on the imapsieve documentation page use COPY but not 
>> APPEND to watch messages coming into a folder. Are there not 
>> circumstances that a client would APPEND a message to a folder instead 
>> of COPY? Is APPEND only used by most clients for adding a sent message 
>> to the sent folder? I'm not familiar enough with IMAP clients to know 
>> if by leaving off APPEND I am safe or I am at risk to miss some 
>> actions I shouldn't.
> 
> Depends on the application. E.g., if you're trying to detect messages
> being moved into the Junk folder, COPY is usually involved. Instead,
> if you're trying to detect messages being put in the Sent folder,
> APPEND is usually involved.

So it shouldn't hurt to add APPEND in an example as on the documentation 
page right? However I believe you would only add it to the first 
"mailbox1" whereas adding the APPEND cause to "mailbox2" should not be 
correct, because it is impossible to APPEND from one folder to another?