Add the possibility of having a custom email sender on Post Functions

Description
While using the Xporter POST function, the Sender email is a default one xporter.reports@getxporter.app.

The Xporter does not provide an option to configure or override it. 

User friction
 

• Users cannot control or specify the sender value
• Customers cannot use a recognized or business-approved sender
• Email recipients are confused by an unfamiliar sender
• Branding and compliance requirements cannot be met

Steps to reproduce (right now) / Actual Result:

• Configure an Xporter export using the Post-function
• Trigger the Workflow post-function
• Inspect the Sender of the email  

Actual result:
The sender in the email is populated with a default xporter.reports@getxporter.app.
IMPACT

• Emails appear less trustworthy to recipients
• Business or compliance requirements related to email identity cannot be satisfied
• Reduced the effectiveness of workflow-driven notifications

What would improve if solved?

• Admins could configure a known sender name or email address
• Emails would align with customer branding and business needs
• Improved user trust and clarity

Impact on stakeholders:

• End users: Emails are easier to recognize and trust
• Customers: Can meet internal business or branding requirements
• Admins: Greater control over workflow notifications
• Support: Fewer questions about “unknown sender” emails * Improved reliability of outbound integrations 

Current workaround:
Customers accept the default sender or explain to users why emails come from an unfamiliar address.

CONTEXT & EXAMPLES:

Concrete example:
A customer wants workflow emails to come from a specific company name or show a known sender name. Since Xporter always uses the default sender, recipients question the authenticity of the email.
Workaround risk:

• Users may ignore or flag emails as suspicious
• Reduced engagement with Jira notifications
• Customer dissatisfaction due to a lack of customization