Silent failure while trying to upload?

[hirenp]

$ java -jar ./target/mail-importer-0.0.0-SNAPSHOT-jar-with-dependencies.jar --mailbox /home/hiren/email_archive/Maildir/nw/beastie/

I get

SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.

followed by the dump of my gmail mailbox labels etc and the command exits.

what am I missing?

[hirenp]

Hum, my emails are in maildir format with subdirs and leaf having cur/tmp/new dirs. I wonder if thats not a supported format.