Yes messages with prefeix http or www appear after long time and at times after many days. The trick is to not write http or www.

Instead, write the website address as google dot com.

I couldn't send any messages at all . Although, I send many messages to italki about this issue but without any change so I deactivate my old account and create a new one. Problem solved

Yes, I have problem with messages -some messages just get lost , I try use Facebook, with my new friends, because in Italki terrible chat and system of messages , I think so. Sorry for my English

I have noticed that some messages appear to get lost. They finally appear after a week or so. There may be a bad filter setting.