Problems with uploading via wi-fi (ftp, e-mail)?

Question

Computer networks

I use wi-fi in the hotel.
Everything is fine, but when trying to upload, problems arise.
The first 512 bytes of the file are uploaded to ftp, then the connection is cut off.
proftpd server
By the way, ftp itself works only in passive mode.
Letters are sent via email (the bat , smtp via ttls) without attachments, if you send a letter with an attachment, the sending thermometer reaches the end, then a minute of silence, then a thump:!
01/09/2013, 20:20:41: SEND - Message has not been sent. Server reply -
01/09/2013, 20:20:41: FETCH - Connection to host broken (last commands sent were: "DATA", "RSET")
01/09/2013, 20:20:41: SEND - connection finished - 0 messages sent
01/09/2013 20:20:41: SEND - Some messages were not sent - check the log for details

Answer 1

I had a similar problem with wi-fi in a hotel, only the problem was that it was not possible to use https.
Maybe they somehow cut it for security purposes.
Hotspot paid or free? I had problems with the free one. A friend bought access to a paid one for a day and he had no such problems.