By what date are forms 1099-DIV required to be sent to individuals? I am waiting for one from a mutual fund and they claim they have until Feb 15th to mail it.

The 1099-DIV needs to be sent to the recipient by January 31, 2018. 

Per IRS' instructions "Due dates. Furnish Copy B of this form to the recipient by January 31, 2018." See the link below, last page of PDF, under instructions for payer. 

https://www.irs.gov/pub/irs-prior/f1099div--2017.pdf

Just to clarify for future readers, your mutual fund company is correct and the respondent below is incorrect.  For 1099-MISC that report non-employee compensation, the date is Jan. 31.  For other types of 1099, including those from investment companies, the deadline is mid February.