This looks like zero-bytes are getting passed to Tika via dovecot.  I don't know enough about dovecot to figure out what's going on.

On Sat, Jul 30, 2022 at 7:51 PM PGNet Dev <pgnet.dev@gmail.com> wrote:
i'm running

        dovecot 2.3.19.1 + fts
        tika-server-standard 2.4.1

dovecot is feeding tika backend via fts_tika

when dovecot passes data with *.eml attachments embedded, tika fails to correctly parse/extract content

not clear if the issue is with tika, or what dovecot's passing in this case.

other non-.eml attachments are fine.

here's the current failing procedure,

(1)
create a simple pdf

        enscript -p mime.ps /etc/mime.types
        ps2pdf mime.ps mime.pdf

(2)
send an email *with* mime.pdf attachment to

        echo "test" | mailx -s "test" -a ./mime.pdf testuser@example.com

tika processes OK

        journalctl -f -u tika
                ...
                Jul 30 19:09:24 mx-test tika[19682]: INFO  [qtp2112135199-30] 19:09:24,165 org.apache.tika.server.core.resource.TikaResource /tika (application/pdf)
                ...

save the just-received email with .pdf attachment as mime.eml

(3)
send an email with NO .pdf attachment
save the just-received email with .pdf attachment as mime2.eml

(4)
send an email with mime.eml attachment, containing the embedded mime.pdf

        echo "test" | mailx -s "test" -a ./mime.eml testuser@example.com

tika fails to extract message/rfc822

        journalctl -f -u tika | grep -v StatusLogger
                ...
                Jul 30 19:28:00 mx-test tika[20049]: INFO  [qtp2112135199-30] 19:28:00,834 org.apache.tika.server.core.resource.TikaResource /tika (message/rfc822)
                Jul 30 19:28:00 mx-test tika[20049]: WARN  [qtp2112135199-30] 19:28:00,840 org.apache.tika.server.core.resource.TikaResource tika/: Text extraction failed (mime.eml)
                Jul 30 19:28:00 mx-test tika[20049]: org.apache.tika.exception.ZeroByteFileException: InputStream must have > 0 bytes
                Jul 30 19:28:00 mx-test tika[20049]:         at org.apache.tika.parser.AutoDetectParser.parse(AutoDetectParser.java:153) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.apache.tika.parser.ParserDecorator.parse(ParserDecorator.java:152) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.apache.tika.parser.DigestingParser.parse(DigestingParser.java:55) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.apache.tika.server.core.resource.TikaResource.parse(TikaResource.java:352) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.apache.tika.server.core.resource.TikaResource.lambda$produceText$1(TikaResource.java:502) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.apache.cxf.jaxrs.provider.BinaryDataProvider.writeTo(BinaryDataProvider.java:177) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.apache.cxf.jaxrs.utils.JAXRSUtils.writeMessageBody(JAXRSUtils.java:1616) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.apache.cxf.jaxrs.interceptor.JAXRSOutInterceptor.serializeMessage(JAXRSOutInterceptor.java:249) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.apache.cxf.jaxrs.interceptor.JAXRSOutInterceptor.processResponse(JAXRSOutInterceptor.java:122) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.apache.cxf.jaxrs.interceptor.JAXRSOutInterceptor.handleMessage(JAXRSOutInterceptor.java:84) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:307) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.apache.cxf.interceptor.OutgoingChainInterceptor.handleMessage(OutgoingChainInterceptor.java:90) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:307) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.apache.cxf.transport.ChainInitiationObserver.onMessage(ChainInitiationObserver.java:121) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.apache.cxf.transport.http.AbstractHTTPDestination.invoke(AbstractHTTPDestination.java:265) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.apache.cxf.transport.http_jetty.JettyHTTPDestination.doService(JettyHTTPDestination.java:247) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.apache.cxf.transport.http_jetty.JettyHTTPHandler.handle(JettyHTTPHandler.java:79) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:235) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1440) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:190) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1355) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:191) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.eclipse.jetty.server.Server.handle(Server.java:516) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.eclipse.jetty.server.HttpChannel.lambda$handle$1(HttpChannel.java:487) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.eclipse.jetty.server.HttpChannel.dispatch(HttpChannel.java:732) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:479) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:277) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:311) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:105) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.eclipse.jetty.io.ChannelEndPoint$1.run(ChannelEndPoint.java:104) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:338) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:315) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:173) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:131) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:409) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:883) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:1034) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:00 mx-test tika[20049]:         at java.lang.Thread.run(Thread.java:833) ~[?:?]
                Jul 30 19:28:00 mx-test tika[20049]: ERROR [qtp2112135199-30] 19:28:00,845 org.apache.cxf.jaxrs.utils.JAXRSUtils Problem with writing the data, class org.apache.tika.server.core.resource.TikaResource$$Lambda$338/0x0000000800eb4a38, ContentType: text/plain

(5)
send an email with mime2.eml attachment, WITHOUT an embedded .pdf

        echo "test" | mailx -s "test" -a ./mime.eml testuser@example.com

again, tika fails to extract message/rfc822

        journalctl -f -u tika | grep -v StatusLogger
                ...
                Jul 30 19:28:33 mx-test tika[20049]: INFO  [qtp2112135199-30] 19:28:33,607 org.apache.tika.server.core.resource.TikaResource /tika (message/rfc822)
                Jul 30 19:28:33 mx-test tika[20049]: WARN  [qtp2112135199-30] 19:28:33,616 org.apache.tika.server.core.resource.TikaResource tika/: Text extraction failed (mime2.eml)
                Jul 30 19:28:33 mx-test tika[20049]: org.apache.tika.exception.ZeroByteFileException: InputStream must have > 0 bytes
                Jul 30 19:28:33 mx-test tika[20049]:         at org.apache.tika.parser.AutoDetectParser.parse(AutoDetectParser.java:153) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.apache.tika.parser.ParserDecorator.parse(ParserDecorator.java:152) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.apache.tika.parser.DigestingParser.parse(DigestingParser.java:55) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.apache.tika.server.core.resource.TikaResource.parse(TikaResource.java:352) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.apache.tika.server.core.resource.TikaResource.lambda$produceText$1(TikaResource.java:502) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.apache.cxf.jaxrs.provider.BinaryDataProvider.writeTo(BinaryDataProvider.java:177) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.apache.cxf.jaxrs.utils.JAXRSUtils.writeMessageBody(JAXRSUtils.java:1616) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.apache.cxf.jaxrs.interceptor.JAXRSOutInterceptor.serializeMessage(JAXRSOutInterceptor.java:249) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.apache.cxf.jaxrs.interceptor.JAXRSOutInterceptor.processResponse(JAXRSOutInterceptor.java:122) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.apache.cxf.jaxrs.interceptor.JAXRSOutInterceptor.handleMessage(JAXRSOutInterceptor.java:84) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:307) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.apache.cxf.interceptor.OutgoingChainInterceptor.handleMessage(OutgoingChainInterceptor.java:90) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:307) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.apache.cxf.transport.ChainInitiationObserver.onMessage(ChainInitiationObserver.java:121) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.apache.cxf.transport.http.AbstractHTTPDestination.invoke(AbstractHTTPDestination.java:265) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.apache.cxf.transport.http_jetty.JettyHTTPDestination.doService(JettyHTTPDestination.java:247) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.apache.cxf.transport.http_jetty.JettyHTTPHandler.handle(JettyHTTPHandler.java:79) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:235) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1440) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:190) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1355) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:191) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.eclipse.jetty.server.Server.handle(Server.java:516) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.eclipse.jetty.server.HttpChannel.lambda$handle$1(HttpChannel.java:487) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.eclipse.jetty.server.HttpChannel.dispatch(HttpChannel.java:732) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:479) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:277) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:311) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:105) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.eclipse.jetty.io.ChannelEndPoint$1.run(ChannelEndPoint.java:104) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:338) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:315) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:173) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:131) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:409) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:883) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:1034) ~[tika-server-standard-2.4.1.jar:2.4.1]
                Jul 30 19:28:33 mx-test tika[20049]:         at java.lang.Thread.run(Thread.java:833) ~[?:?]
                Jul 30 19:28:33 mx-test tika[20049]: ERROR [qtp2112135199-30] 19:28:33,630 org.apache.cxf.jaxrs.utils.JAXRSUtils Problem with writing the data, class org.apache.tika.server.core.resource.TikaResource$$Lambda$338/0x0000000800eb4a38, ContentType: text/plain

(6)
submit mime.eml directly to tika

        curl -T ./mime.eml http://127.0.0.1:9998/tika
        journalctl -f -u tika | grep -v StatusLogger
                ...
                Jul 30 19:30:08 mx-test tika[20049]: INFO  [qtp2112135199-34] 19:30:08,073 org.apache.tika.server.core.resource.TikaResource /tika (autodetecting type)

(7)
submit mime2.eml directly to tika

        curl -T ./mime2.eml http://127.0.0.1:9998/tika
        journalctl -f -u tika | grep -v StatusLogger
                ...
                Jul 30 19:30:52 mx-test tika[20049]: INFO  [qtp2112135199-30] 19:30:52,349 org.apache.tika.server.core.resource.TikaResource /tika (autodetecting type)

(8)
where,

        cat mime.eml
                Return-Path: <msmtp@pgnd.example.com>
                Delivered-To: testuser@example.com
                ...
                From: msmtp@pgnd.example.com
                Date: Sat, 30 Jul 2022 18:53:38 -0400
                To: testuser@example.com
                Subject: test
                User-Agent: Heirloom mailx 12.5 7/5/10
                Content-Type: multipart/mixed;
                 boundary="=_62e5b672.wAyBX+sGMbS7ZcNv8O/A1QeYuseaJ2NDRf8hfdbm/x8Vayp+"
                Message-Id: <4LwKS35QWSzWf3Q@mx-test.example.com>

                This is a multi-part message in MIME format.

                --=_62e5b672.wAyBX+sGMbS7ZcNv8O/A1QeYuseaJ2NDRf8hfdbm/x8Vayp+
                Content-Type: text/plain; charset=us-ascii
                Content-Transfer-Encoding: 7bit
                Content-Disposition: inline

                test

                --=_62e5b672.wAyBX+sGMbS7ZcNv8O/A1QeYuseaJ2NDRf8hfdbm/x8Vayp+
                Content-Type: application/pdf
                Content-Transfer-Encoding: base64
                Content-Disposition: attachment;
                 filename="mime.pdf"

                JVBERi0xLjQKJcfsj6IKJSVJbnZvY2F0aW9uOiBwYXRoL2dzIC1QLSAtZFNBRkVSIC1kQ29t
                ...
                Rgo=

                --=_62e5b672.wAyBX+sGMbS7ZcNv8O/A1QeYuseaJ2NDRf8hfdbm/x8Vayp+--

and,

        cat mime2.eml
                Return-Path: <msmtp@pgnd.example.com>
                Delivered-To: testuser@example.com
                ...
                From: msmtp@pgnd.example.com
                Date: Sat, 30 Jul 2022 19:14:59 -0400
                To: testuser@example.com
                Subject: test
                User-Agent: Heirloom mailx 12.5 7/5/10
                Content-Type: text/plain; charset=us-ascii
                Content-Transfer-Encoding: 7bit
                Message-Id: <4LwKwh5brVzWf3Q@mx-test.example.com>

                test