TCPing should work. I have found it very useful.

Simplest form: tcping.exe host port

Numerous options are available. I use this a lot to just check a port quickly.

Assuming you want to transfer a file securely to someone, just use 7-zip and compress the file using AES encryption and a secure password (20+ chars, mixed letters and symbols, no dictionary words). Then email the file. But use a different method to send the password. Also you have to be concerned about the maximum size of an email that the recipient's mail system will accept.

But any way you look at it, if you need to get the file into someone's mailbox securely, then you need to encrypt it separately.

XCA is another GUI tool for managing certs, just to get the link into the conversation. It makes a lot of more complex operations simple, not just for cert creation. It will keep track of the association of intermediate and root certs, let you import and export different formats, etc. Similar to the OpenSSL Wizard that BGM noted.