Testing mail using cURL

List messages in the INBOX over IMAP(S):

curl -k -v --url 'imaps://mail.example.com:993' --user 'admin@example.com:setup' --request "EXAMINE INBOX"

Send a message over SMTP+STARTTLS:

curl -k -v --url 'smtp://mail.example.com:25' --user 'admin@example.com:setup' --ssl-reqd --mail-from 'admin@example.com' --mail-rcpt 'admin@example.org' --upload-file message

Retrieve unused IP addresses in Plesk via CLI

Retrieve a list of domains and their IP addresses:

plesk db "SELECT d.name, IF(ip.public_ip_address IS NULL, ip.IP_Address, ip.public_ip_address) AS 'IP' FROM domains d JOIN DomainServices ds ON d.id=ds.dom_id JOIN IpAddressesCollections ipc USING(ipCollectionId) JOIN IP_Addresses ip ON ipc.ipAddressId=ip.id WHERE ds.type='web';"

Retrieve unused IP addresses in Plesk via CLI:

plesk bin ipmanage -l | awk '{ if ($4 == 0 && $5 == 0) { print } }'