Mark Morgan Lloyd offers the following solution.
Oscput appears in the terminal window rather than scput, after which the upload is screwed. It's a known problem when connecting via telnet and presumably could occur on other types of link- the consensus is that it's caused by a slow connection but allowing for the increase in modem speed etc. over the last few years I think it's more likely to be caused by a jerky one, or to be a bug in the telnet code in Ameol.
I don't know why, but the debugging profile cures the message-upload problem. However, I've on one occasion seen an Oscput in a different context that wasn't caught by the same hack- I can't remember the details but it may have been when I was sending email with an attachment (i.e. as distinct from binmail).
I've yet to see a version of Wine in which tabbed dialogs work. This is inconvenient for Ameol users, as Ameol uses a number of such dialogs for configuration.
However, Steve Lockhart has a solution:
Settings, Customise,then click on the font tab, then select
Settings, Customiseagain.