Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2015	Nov. 09, 2015
Document And Entity Information
Entity Registrant Name	SMTP, Inc.
Entity Central Index Key	0001506439
Document Type	10-Q
Document Period End Date	Sep. 30, 2015
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		7,233,050
Trading Symbol	SMTP
Document Fiscal Period Focus	Q3
Document Fiscal Year Focus	2015