I have never had any problems. I don't get many spreadsheets attached to emails, but I usually get one or two a month. And I just did a test of sending one to myself, worked just fine - can you send one to yourself?. It is not clear to me, are you not getting the email at all, or just not the attachment?
Sorry, but I don't have any ideas why you are experiencing a problem (well, maybe one - any chance you have a rule set up in your email client to exclude certain kinds of attachments, like spreadsheets?).
I may have a 'go around' solution you can use until the problem is fixed. Try renaming the file extension. IOW, instead of "test.xls", rename the file to "test.bls." Whatever filter is preventing the Excel attachments from going through might be fooled by this.
Of course, you'll have to let the recepient of the e-mail know that he/she must download and then rename the file back to test.xls before trying to open it.
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