This is what my postfix server says:

Nov 28 14:23:12 albus postfix/qmgr[654]: 823D71CDE2714: from=gerben.wierda@rna.nl, size=9144, nrcpt=1 (que ue active) Nov 28 14:23:12 albus postfix/smtp[2294]: Untrusted TLS connection established to talvi.dovecot.org[94.237.1 05.223]:25: TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (prime256v1) server -signature RSA-PSS (2048 bits) server-digest SHA256 Nov 28 14:23:13 albus postfix/smtp[2294]: 823D71CDE2714: to=dovecot@dovecot.org, relay=talvi.dovecot.org[9 4.237.105.223]:25, delay=2.1, delays=0.51/0.02/0.75/0.83, dsn=2.0.0, status=sent (250 2.0.0 Ok: queued as E5 C425DEEF) Nov 28 14:23:13 albus postfix/qmgr[654]: 823D71CDE2714: removed

But I can't see it here nor do I get it sent back to me.