SMTP floods from 185.222.211.11 / 2019-06-08

Noticed in the recent logs, lots of variations on:

Jun  6 19:15:41 gosper sm-mta[22475]: x56HFc06022475: <mail@some.domain>... No such user in domain 
Jun  6 19:15:41 gosper sm-mta[22475]: x56HFc06022475: <support@some.domain>... No such user in domain 
Jun  6 19:15:41 gosper sm-mta[22475]: x56HFc06022475: <reply@some.domain>... No such user in domain 
Jun  6 19:15:41 gosper sm-mta[22475]: x56HFc06022475: srv-eml.info [185.222.211.11]: Possible SMTP RCPT flood, throttling.
Jun  6 19:15:41 gosper sm-mta[22466]: x56HFCbH022466: <financeiro@some.domain>... No such user in domain 
Jun  6 19:15:42 gosper sm-mta[22473]: x56HFVoi022473: <biuro@some.domain>... No such user in domain 
Jun  6 19:15:42 gosper sm-mta[22468]: x56HFItg022468: <michael@some.domain>... No such user in domain 
Jun  6 19:15:42 gosper sm-mta[22471]: x56HFPIC022471: <chris@some.domain>... No such user in domain 
Jun  6 19:16:51 gosper sm-mta[22466]: x56HFCbH022466: lost input channel from srv-eml.info [185.222.211.11] to MTA-v6 after rcpt
Jun  6 19:17:16 gosper sm-mta[22475]: x56HFc06022475: <jobs@some.domain>... No such user in domain 
Jun  6 19:17:17 gosper sm-mta[22475]: x56HFc06022475: <wh5gkoxp5wqk@some.domain>... No such user in domain 
Jun  6 19:17:18 gosper sm-mta[22475]: x56HFc06022475: lost input channel from srv-eml.info [185.222.211.11] to MTA-v6 after rcpt
Jun  6 19:17:18 gosper sm-mta[22475]: x56HFc06022475: from=<20tv13b4bu0h2107@europcar.ua>, size=0, class=0, nrcpts=1, proto=ESMTP, daemon=MTA-v6, relay=srv-eml.info [185.222.211.11]

All from the same IP, trying a lot of addresses (and failing), with a retry later trying all those addresses again.