could be lost/could have been lost

[Saneta]

1.Snail mail is not as safe as registered mail, and before I sent filled forms by registered mail I had done xerox of these filled forms, in the case of those original filled printed forms could be lost.

2.Snail mail is not as safe as registered mail, and before I sent filled forms by registered mail I had done xerox of these filled forms, in the case of those original filled printed forms could have been lost.

which sentence is correct and why?

thanks

[Dozy]

Neither is right. There are a number of problems. You can say:

"X is not as safe as Y, and before I send filled forms by X I xerox them in case the originals are lost (in the post)." -- This is your general practice.

"X is not as safe as Y, and before I sent the filled forms by X I xeroxed them in case the originals were lost (in the post)." -- You did this on a particular past occasion.

You need to choose X and Y that make sense, which in your sentences isn't the case. Note that "snail mail" refers to physical mail as opposed to electronic mail, not to a particular type of physical mail.

I left "filled", but it is hardly necessary. It would be assumed. In BrE the verb "xerox" is hardly used and seems old-fashioned to me. I would say "copy" or "photocopy". I'm not sure about AmE.

[Saneta]

thanks dozy!
You need to choose X and Y that make sense, which in your sentences isn't the case.

which in your sentences isn't the case=which in your sentences isn't the most important thing/point?

thanks again!!!

[Dozy]

"... which in your sentences isn't the case" = "... which isn't true in your sentences" (i.e., in your sentences X and Y do not make sense).