Thank you, Egidio, for your response to my query - it is much appreciated. Regrettably it has not enabled me to open the TIFF files. Perhaps it is because I am 75 years old and not computer literate. Well, not Apple.Mac literate that is, for I had no insurmountable problems with my PC using Windows over the previous 12 years.
Following your guidance, I tried 'Command + I' to obtain information about the TIFF files. The first time I tried I obtained a list of Headings starting with File Name: Document type: File Size: etc. However, there was a blank space against all of them - and I didn't see a heading of "Open With". When I subsequently tried several times to repeat "Command + I" on the same file and with 5 different TIFF files, I received no response at all.
'Control + Click' then 'Open with" provided a list of applications to open the file. None of them worked.
HP Image Print returned: There was a problem with the file Image.Tiff.
Jpeg to IPhoto: Opened IPhoto and the HP Image Dropper window with the HP Logo showing but no image to drag across to the IPhoto screen.
Safari returned: A long address in the address box but a blank screen below.
Quick Time returned: The movie could not be opened.
Preview returned: Couldn't open file. It may be corrupt or a file format that Preview doesn't recognise.
Graphic Converter returned: The file 'Image.tiff' is empty (zero length). So it can't be opened.
The impression I gain from this is that the TIFF attachments don't actually contain any images. However, I do not believe this to be the case. Nonetheless, I have returned the most recent three e-mails to the sender and asked for confirmation that he can open the attachments on his machine.
Until I hear from the sender of the TIFF attachments there seems little point in pursuing this problem further. However, if it is confirmed that the TIFF Images do actually contain an image (and I don't see how they could not) I would appreciate it if I could call on your expertise again.
Kinds Regards
Audel42