tools/c7n_mailer - use utf-8 encoding for slack delivery (#7167)
tools/c7n_mailer - use utf-8 encoding for slack delivery (#7167)


thisisshi/cloud-custodian,thisisshi/cloud-custodian,alfredgamulo/cloud-custodian,alfredgamulo/cloud-custodian,alfredgamulo/cloud-custodian,thisisshi/cloud-custodian