3445061 - E-Mail Output Error 554 5.0.0 Transaction failed: Illegal filename

In the status of an email outbound, you see an error 554 5.0.0 Transaction failed: Illegal filename.

SAP Business ByDesign

The email error  indicates the following

Diagnostic-Code: smtp; 554 5.0.0 Transaction failed: Illegal filename
'Module1.vb'. in aws
https://community.sap.com/t5/enterprise-resource-planning-blogs-by-sap/next-generation-cloud-delivery-transition-new-business-bydesign-e-mail/ba-p/13523279#comment-631565

Please check above link:

What are the attachment types that are “NOT Allowed” at our e-mail server?

E-mails containing one of the following file types currently fall into the category “dangerous attachment”:
ade, adp, app, asp, bas, bat, bhx, cab, ceo, chm, cmd, com, cpl, crt, csr, der, exe, fxp, hlp, hta, inf, ins, isp, its, js, jse, lnk, mad, maf, mag, mam, mar, mas, mat, mde, mim, msc, msi, msp, mst, ole, pcd, pif, reg, scr, sct, shb, shs, vb, vbe, vbmacros, vbs, vsw, wmd, wmz, ws, wsc, wsf, wsh, xxe, docm, xlsm.

This also applies if attachments with these extensions are found in the following (password-protected) archives:
arj, cab, jar, lha, rar, tar, zip, gz

Please follow the guideline for allowed attachment.

email error, attachments, email status error,554 5.0.0 Transaction failed: Illegal filename , KBA , AP-RC-OUT , Output Management , How To