"Google, and Twitter and Facebook, they are really treading on very, very troubled territory, and they have to be careful."
The US president's travel ban, which generated a public outcry, temporarily barred visitors and immigrants from seven majority Muslim countries.
He claimed it was needed to protect the US from Islamist militants.
The Supreme Court upheld the measure in June.
The emails reveal Google employees proposed ways to "leverage" search functions to counter "Islamophobic, algorithmically biased results from search terms 'Islam', 'Muslim', 'Iran', etc" as well as "biased search results from search terms such as 'Mexico', 'Hispanic', 'Latino"'.
They show an internal debate inside the company over the proposed intervention. One employee wrote: "we're absolutely in...Anything you need."
A Google spokesman said the emails represented brainstorming and none of the ideas was implemented.
She said the company did not manipulate search results or modify products to promote political views."Our processes and policies would not have allowed for any manipulation of search results to promote political ideologies," the spokesman said in a statement.