ColdFusion send mail resource not found - email

Question

I am sending mails in coldfusion as below. But some of my emails being sent are thrown out with the exception below:
<cfif !IsNull(SignatureDetails) && len(trim(SignatureDetails.getDigitalSignature()))>
<!--- Embed digital signature if present via the local file system. --->
<cfset variables.signatureUrl = '../../../urls/files/messages/spreadsheet/rows/columns/' & #SignatureDetails.getDigitalSignature()#>
<cfmailparam file="#ExpandPath('#variables.signatureUrl#')#" contentid="digitalSignature" disposition="inline"/>
</cfif>
And the exception:
object.email.sendTemplateEmail: The resource C:\Data\map\urls\files\messages\spreadsheet\rows\columns\column.jpg was not found. The root cause was: ''.
The correct path should be: C:\Data\urls\files\messages\spreadsheet\rows\columns\column.jpg
The issue is that it is only happening on a select few emails being sent. The directory is hardcoded as above while the name of the signature is pulled from a table in my db.

Answer 1

The problem seems to be the use of relative pathing in this line
<cfset variables.signatureUrl = '../../../urls/files/messages/spreadsheet/rows/columns/' & #SignatureDetails.getDigitalSignature()#>
It is possible that the code is being run from a slightly different directory path depending on the page being executed, as such, going up 3 directories may not give you the path you are looking for. When ColdFusion cannot find a path as you have defined, it appends the know path to the end of the path in which the file being processed exists.
You can correct this by creating a mapping to the signatures (or attachments directory) directory (you define the mapping in Application.cfc) and using this to add the signature.
For mapping pointing to 'signatures' and named 'signatures'
<cfset variables.signatureUrl = '/columns/' & SignatureDetails.getDigitalSignature()>
For mapping pointing to 'attachments' and named 'attachments'
<cfset variables.signatureUrl = '/rows/columns/' & SignatureDetails.getDigitalSignature()>
If you need information about creating mappings in Application.cfc, please check this link.