This is embarrassing how many times I have had to look this up. Writing it down this time, so atleast I know for sure where I can find the info.

Let's say you have a table named people_info with one of the columns called email:

email
varun@work.com
cdain3@qq.com
varunsomeone@gmail.com
poseidon@yahoo.co.in
special_varun@yahoo.com
areswashere@aol.com
varun+unique@example.com
trash@varunbarad.com

Now we only want rows where email contains the sub-string varun.

select email
from people_info
where email like '%varun%';

This now gives us:

email
varun@work.com
varunsomeone@gmail.com
special_varun@yahoo.com
varun+unique@example.com
trash@varunbarad.com