It seems that there isn't way how to sent an e-mail using SMTP directly by JavaScript webhook (or maybe it is, but just not more explicitly documented?):

https://www.zabbix.com/documentation/devel/en/manual/config/items/preprocessing/javascript/javascript_objects

https://duktape.org/guide.html

It would be great, if it would be supported in ZBX somehow, as it could overcome another limitation of external alert scripts, as webhook directly supports much wider range of input system macros (e.g. {EVENT.TAGS.<tag name>}), while media type script supports only {ALERT.*} ones:

https://www.zabbix.com/documentation/current/en/manual/config/notifications/media/webhook

https://www.zabbix.com/documentation/current/en/manual/config/notifications/media/script

while only workarounds by parsing of e-mail subject/body seem possible:

https://support.zabbix.com/browse/ZBXNEXT-3185

https://support.zabbix.com/browse/ZBX-12370

Maybe enabling using of sockets would be enough, not just for sending e-mails via SMTP, but also for using variety of other protocols from webhooks, maybe something like?:

https://zetcode.com/javascript/socket/

https://extendscript.docsforadobe.dev/external-communication/socket-object.html

Here is also mentioned some hyphotetical Socket object:

https://wiki.duktape.org/howtofinalization

Thanks in advance for any response.