evolution - PGP key manager - Ask Ubuntu

i have 2 vmware machines on player..

first ubuntu email client evolution have generated key in seahorse on email a@xxx.com

second windows email client thunderbird have generated key enigmail on email b@xxx.com

what want send encrypted , signed emails a@xxx.com b@xxx.com , reply a@xxx.com b@xxx.com

with enigmail have downloaded public key b@xxx.com , can see it.

problem simple: when send email thunderbird a@xxx.com signed , encrypted b@xxx.com works fine , can see message.

but when try reply b@xxx.com (evolution mail client) a@xxx.com (thunderbird mail client) error:

: because "gpg: using subkey xxxxxxxx instead of primary key xxxxxxxxxx gpg: no trust check due '--trust-model always' option gpg: : skipped: no public key gpg: [stdin]: encryption failed: no public key ", may need select different mail options.

problem cant reply b@xxx.com a@xxx.com of error ^^^^