I'm using the KOMA scrletter package to embed a letter into another document, see the following MWE:
\documentclass[12pt,ngerman]{scrartcl}
\usepackage{fontspec}
\usepackage{polyglossia}
\setdefaultlanguage[babelshorthands=true]{german}
\usepackage{blindtext}
\usepackage{scrletter}
\rohead{My heading \\ Max Mustermann}
\begin{document}
\blindtext[3]
\setkomavar{fromname}{Max Mustermann}
\setkomavar{fromaddress}{Musterstr. 12 \\ 12345~Musterstadt}
\setkomavar{place}{Musterstadt}
\setkomavar{subject}{Subject ..}
\begin{letter}{Martina Musterfrau \\ Musterweg 4 \\ 12346~Musterdorf}
\opening{Sehr geehrte Damen und Herren,}
\closing{Mit freundlichen Grüßen,}
\end{letter}
\blindtext[3]
\end{document}
The surrounding scrartcl document uses an own pagestyle with individual header, defined with \rohead{...}.
However, on the letter page, the header is not displayed.
How can I make the original header to display on all pages, especially on the letter page?

letter, pagestyle of first page isempty. Use\pagestyle{scrheadings}after\opening. – Johannes_B Mar 14 '16 at 15:26\thispagestyle{scrheadings}after\openingand may be \setkomavar{firsthead}{}`. – esdd Mar 14 '16 at 15:38