Report of Independent Registered Public Accounting Firm

To the Shareholders and
Board of Trustees of MFS Series Trust VI

In planning and performing our audit of the financial statements of MFS
Global Equity Fund, MFS Global Total Return Fund and MFS Utilities Fund
(the "Funds") (three of the series constituting MFS Series Trust VI (the
"Trust")) as of and for the year ended October 31, 2021, in accordance
with the standards of the Public Company Accounting Oversight Board
(United States), we considered the Trust's internal control over
financial reporting, including controls over safeguarding securities,
as a basis for designing our auditing procedures for the purpose of
expressing our opinion on the financial statements and to comply with
the requirements of Form N-CEN, but not for the purpose of expressing
an opinion on the effectiveness of the Trust's internal control over
financial reporting. Accordingly, we express no such opinion.
The management of the Trust is responsible for establishing and
maintaining effective internal control over financial reporting. In
fulfilling this responsibility, estimates and judgments by management
are required to assess the expected benefits and related costs of
controls. A company's internal control over financial reporting is a
process designed to provide reasonable assurance regarding the
reliability of financial reporting and the preparation of financial
statements for external purposes in accordance with U.S. generally
accepted accounting principles. A company's internal control over
financial reporting includes those policies and procedures that
(1) pertain to the maintenance of records that, in reasonable detail,
accurately and fairly reflect the transactions and dispositions of the
assets of the company; (2) provide reasonable assurance that transactions
are recorded as necessary to permit preparation of financial statements
in accordance with U.S. generally accepted accounting principles, and
that receipts and expenditures of the company are being made only in
accordance with authorizations of management and directors of the
company; and (3) provide reasonable assurance regarding prevention or
timely detection of unauthorized acquisition, use or disposition of a
company's assets that could have a material effect on the financial
statements.
Because of its inherent limitations, internal control over financial
reporting may not prevent or detect misstatements. Also, projections of
any evaluation of effectiveness to future periods are subject to the risk
that controls may become inadequate because of changes in conditions, or
that the degree of compliance with the policies or procedures may
deteriorate.
A deficiency in internal control over financial reporting exists when
the design or operation of a control does not allow management or
employees, in the normal course of performing their assigned functions,
to prevent or detect misstatements on a timely basis. A material weakness
is a deficiency, or a combination of deficiencies, in internal control
over financial reporting, such that there is a reasonable possibility
that a material misstatement of the company's annual or interim
financial statements will not be prevented or detected on a timely basis.
Our consideration of the Trust's internal control over financial
reporting was for the limited purpose described in the first paragraph
and would not necessarily disclose all deficiencies in internal control
that might be material weaknesses under standards established by the
Public Company Accounting Oversight Board (United States). However, we
noted no deficiencies in the Trust's internal control over financial
reporting and its operation, including controls over safeguarding
securities, that we consider to be a material weakness as defined above
as of October 31, 2021.
This report is intended solely for the information and use of management
and the Board of Trustees of MFS Series Trust VI and the Securities and
Exchange Commission and is not intended to be and should not be used by
anyone other than these specified parties.

/s/ Ernst & Young LLP
Boston, Massachusetts
December 15, 2021