Enable support for SMTP destinations

Packages describing “smtp” as local USE flag

Package “smtp” Flag Description
app-admin/syslog-ng Enable support for SMTP destinations
net-analyzer/echoping enable support for SMTP protocol.
net-libs/libwebsockets Provide SMTP support
mail-client/mutt Enable support for direct SMTP delivery
dev-libs/log4cxx Offer SMTP support via net-libs/libesmtp
sys-cluster/pacemaker Enable SMTP support via net-libs/libesmtp
net-misc/curl Enable Simple Mail Transfer Protocol support
app-admin/sagan Build witch SMTP (E-Mail) support

All packages providing a “smtp” USE flag (6)