The default setting for Alma letters is "Dear Sir/Madame." To change it to Dear Firstname Lastname, do this:
1. Configuration => General => Letters => Components Configuration
Find "mailReason.xsl Letter"
Edit
Enable Code dear and enter "Dear" in the Description.
Save.
2. Configuration => General => Letters => Components Configuration
Find "Mail Reason Letter XSL"
Edit
Enter this Content:
<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template name="toWhomIsConcerned">
<table cellspacing="0" cellpadding="5" border="0">
<tr>
<td>
<xsl:for-each select="notification_data">
<h3>@@dear@@  <xsl:value-of select="receivers/receiver/user/first_name"/> <xsl:value-of select="receivers/receiver/user/last_name"/></h3>
</xsl:for-each>
</td>
</tr>
</table>
</xsl:template>
</xsl:stylesheet>
Save.