Here is an example, with a customer of Network Solutions.
My host is Network Solutions - yesterday they sent an e-mail reading
We are aware of an issue with FTP and UNIX packages. They will generally deny the first connection, but allow subsequent connections. We are requesting that our customers attempt to connect to their server twice until we have a resolution.
Blogger isn't going to (in reality, they can't, reliably) tweak their FTP publishing process to repeatedly attempt a connection with a host server, just because the operators can't solve their own server problems. This is a case where the customers have to get involved, and convince the server operators to fix their server problems.
>> (Update 8/25 5:00): It appears that this problem was related to security at Network Solutions.
Blogger publishes with "passive FTP". To overcome this, Network Solutions identified the IP addresses from which Blogger publishes, then "white-listed" those addresses to its servers so they would accept FTP uploads from Blogger.
>> (Update 8/4 14:00): We have an interesting communication (edited) from Network Solutions.
Hi this is Connie at Network Solutions. I’m writing to affirm that our engineering team is aware of the issue and they’re working diligently to resolve it. It’s a short-term issue, and we’re sorry about the difficulties you’ve experienced along the way. If you would, please try to reconnect to your server. If you continue to run into a snag please contact me at (email address edited).