Section 906 Certifications
I, Charles E. Porter, the Principal Executive Officer of the Funds listed on Attachment A, certify that, to my knowledge:
1. The form N-CSR of the Funds listed on Attachment A for the period ended July 31, 2007, fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and
2. The information contained in the Form N-CSR of the Funds listed on Attachment A for the period ended July 31, 2007 fairly presents, in all material respects, the financial condition and results of operations of the Funds listed on Attachment A.
Date: September 27, 2007
/s/ Charles E. Porter
______________________
Charles E. Porter
Principal Executive Officer
Section 906 Certifications
I, Steven D. Krichmar, the Principal Financial Officer of the Funds listed on Attachment A, certify that, to my knowledge:
1. The form N-CSR of the Funds listed on Attachment A for the period ended July 31, 2007 fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and
2. The information contained in the Form N-CSR of the Funds listed on Attachment A for the period ended July 31, 2007 fairly presents, in all material respects, the financial condition and results of operations of the Funds listed on Attachment A.
Date: September 27, 2007
/s/ Steven D. Krichmar
______________________
Steven D. Krichmar
Principal Financial Officer
| Attachment A | |||
| N-CSR | |||
| Period (s) ended July 31, 2007 | |||
| 073 | Putnam Premier Income Trust | ||
| 2AQ | Putnam Research Fund | ||
| 003 | Putnam Investors Fund | ||
| 007 | Putnam Voyager Fund | ||
| 006 | Putnam Vista Fund | ||
| 036 | Putnam Tax Free High Yield Fund | ||
| 035 | Putnam AMT-Free Insured Municipal Fund | ||
| 024 | Putnam OTC & Emerging Growth Fund | ||
| 2AP | Putnam Growth Opportunities Fund | ||
| 001 | The George Putnam Fund of Boston | ||
| Putnam RetirementReady – Funds | |||
| 7CR | Putnam RetirementReady --2050 | ||
| 40M | Putnam RetirementReady – 2045 | ||
| 40F | Putnam RetirementReady --2040 | ||
| 49Y | Putnam RetirementReady – 2035 | ||
| 49R | Putnam RetirementReady – 2030 | ||
| 49K | Putnam RetirementReady – 2025 | ||
| 49D | Putnam RetirementReady --2020 | ||
| 48W | Putnam RetirementReady – 2015 | ||
| 48I | Putnam RetirementReady – 2010 | ||
| 48P | Putnam RetirementReady --Maturity Fund | ||