Products.easynewsletter

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- Add preview parameter to _render_output_html, which can be used to distinguish preview from email rendering
[MrTango]

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- use email_validator.validate_email in plone_user vocab, fixes 159
[MrTango]

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- Fix dublicate text in action buttons on newsletter-subscribers view.
[MrTango]

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- Don't fail sending process when one email fails
[thomasmassmann]

- Fix helper method: get_results_from_aggregation_sources, which can be used for a table of contents
[MrTango]

- Update output_blacksee template with a TOC and some CSS cleanup
[MrTango]

- Switch from travis to Github-Actions and fix tests
[MrTango]

- Fixed empty epilog error 162
[iham]

- Add Newsletter title to the unsubscribe email subject 131
[MrTango]

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- Add userid to member property dict for plone subscribers.
[thomasmassmann]

- Add information about sent emails to Newsletter Issue.
[thomasmassmann]

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- Force immediate sending in MailHost
[MrTango]

- Add portal messages with send_counter/send_error_counter
[MrTango]

- Add divers for salutation and make salutation optional in subscriber portlet
[MrTango]

- Refacture locales/update.py and fix german translations
[MrTango]