Many thanks for your email (below) explaining what has happened. I now understand why my account would have been deleted.
I checked back to the New Terms and Conditions of Use as at 2013-11-11 that I was obliged to agree to if I wished to continue using the "free" service, per the startup notice in the Tresorit application at that time.
Though I had not noticed it, the Ts & Cs clearly state (sXIV):
XIV Inactive Free Accounts
62. If You have chosen a plan with no charge ("Free Account") and if Your Free Account was inactive for at least one-hundred and twenty (120) days and no valid User Plan is bound to Your Free Account, Tresorit will send You a notice. Fifteen (15) days after such notice, Tresorit may suspend Your Free Account or delete all of Your Content related to Your Free Account, and/or we may terminate the Agreement between You and Tresorit.
However, this point is not mentioned (though it arguably should have been) in section XIX Termination by Tresorit.
I could find no email in my inbox from Tresorit giving notice of imminent account deletion. However, after digging into my email backup archive, I discovered in the archive that I had received one email from Tresorit (not 3 as you suggest) giving 15 days' notice of account deletion/termination. I had not seen this email at the time - it was at a point when I had been away and came back to an overflowing mailbox, and I suspect the Tresorit email was inadvertently picked up as spam and deleted. My apologies.
Nevertheless, the Ts & Cs clearly state "‚Ä¶will send You a notice", and one notice had indeed been sent, so I can't fault Tresorit on that score.
So, back to the possibility of recovering my deleted Tresorit. Is it the case that it is physically impossible to restore it? I had always regarded the definition of "secure storage" as meaning just that - i.e., secure/permanently fixed - barring potential accidental loss/fire, Acts of God, etc.
So, could you please advise whether you will, or refuse, to restore the deleted Tresorit from backup?
As an "early adopter", I joined Tresorit on 2013-04-12 with the sincere belief and on the understanding that Tresorit offered secure, reliable, and encrypted storage - and I advised many people to consider putting their storage with Tresorit for FREE. I am now embarrassed to have to tell them that I had made a huge (albeit genuine) mistake about the Ts & Cs. For example, please refer to Tresorit - Cloud storage service (FREE) - Mini-Review. (WARNING!)
By the way, I have tried, but am still unable to access my account, though you say it should be accessible now. I shall keep trying. Maybe I am doing something wrong? Could you please tell me the precise procedure I need to follow?
Thankyou in anticipation.