The text you typed is too long. Please shorten it and try to save it again error in OWA email signature.
If you are getting “The text you typed is too long. Please shorten it and try to save it again” error while adding an email signature to OWA, probably you are trying to paste an html signature that has more than 4000 characters.
You can increase the length of maximum characters, to do it
Stop the IIS service first (iisreset /stop) then open C:\Program Files\Microsoft\Exchange Server\V14\ClientAccess\ecp\customize folder and open the file EMailSignature.ascx – in notepad
find the line contains
<ecp:RichTextEditor ID=”rteSignatureHtml” runat=”server” DataBoundProperty=”SignatureHtml” MaxLength=”4000″ SetRoles=”Set-MailboxMessageConfiguration?SignatureHtml@W:Self” />
and increase the MaxLength to a reasonable size, e.g 8192, then Save the file and start the IIS (iisreset /start)
But my personal recommendation is simplifying and minifying the HTML code, it could really decrease the size of the file, especially if it has generated by visual tools.
Hope it helps