One of my clients asked me to forward writing samples and resume to an email address, even though I shared those with him via the messaging option in upwork. What should I do?
Have you been officially hired by this client? Does the job show up under "My Jobs" on your account page? If so, it's fine to use alternative email addresses to send files to clients.
If you are just in an interview stage with this client, simply direct them to your profile and portfolio, which should be enough.
Do not send free samples - that is what your portfolio is for.
It seems a little odd since you've shared your samples with them. Although a bit strange, so far.... I see nothing wrong, but you should keep on your toes.
Do not do any work specific to the job and that also includes tests and job specific samples.
Do not give out any personal information, even your address. and especially not your bank account or credit card/Paypal info, SS#, visa or passport information.
Any mention of google hangouts, equals scam.
Do not accept payment outside of Upwork. ALL financial transactions (funding of escrow) MUST take place on this site.
And that also goes for hiring. A contract must be presented on this site.
And do not pay for any laptops, software for the job, work fees, tax specific to a country and/or registration fees.