theHarvester - Email and Subdomain Harvesting
All sources
theHarvester -d google.com -b all
Selected engines
theHarvester -d INE -b duckduckgo,baidu,bing
theHarvester -d offsec.com -b duckduckgo,baidu,bing
With result limit
theharvester -d microsoft.com -b google -l 5