sendmail with esp32 + w5500

as my esp32 device is located in a place where there is no reliable wifi, i would like to use wired lan to send status emails.

therefore i attached a w5500 shield. wiring is ok as with the same hardware, i am able to run a chatserver on the device.

i use the ethernet3 library for the w5500 and now i added the emailsender library.

i tried to use the code according to some examples i found in the net, but it looks like i don’t get any packets out of the w5500. at least my router reports no data at all coming from  the ip of the device.

i would like to send with smtp, using either a gmail or gmx account. i tried both smtp server configurations but always get the status information:

0
2
Could not connect to mail server

but i don’t think that my device even tries to connect to an smtp server as i register no packets coming from it.

is there a setup example for using with the w5500 somewhere?

i tried for hours but have no more ideas how to go on… ;-(