const
    LineBreak: String = #13#10;
    DoubleLineBreak: String = LineBreak+LineBreak;

...

var
    MessageEmail: TIdMessage;
    SMTP: TIdSMTP;
    SSL: TIdSSLIOHandlerSocketOpenSSL;
    Attach: TIdAttachment;
    AttachFile: TIdAttachmentFile;
    AttachMemory: TIdAttachmentMemory;
    StreamFile: TMemoryStream;
        procedure SMTP_PrepareSSL();
        begin
        SSL:=TIdSSLIOHandlerSocketOpenSSL.Create(nil);
        try
            SSL.SSLOptions.Method:=sslvTLSv1;
            SSL.SSLOptions.Mode:=sslmUnassigned;
            SSL.SSLOptions.VerifyMode:=[];
            SSL.SSLOptions.VerifyDepth:=0;
        except
            on Error: EException do
                FreeAndNil(SSL);
                // Logging('SMTP_PrepareSSL', Error);
                raise Error;
            end;
        end;
        procedure SMTP_PrepareSMTP();
        begin
        SMTP_PrepareSSL();
        SMTP:=TIdSMTP.Create(nil);
        try
            SMTP.IOHandler:=SSL;
            SMTP.Host:=TSMTP;
            SMTP.Port:=TPort;
            SMTP.username:=Username;
            SMTP.password:=Password;
            SMTP.UseTLS:=utUseExplicitTLS;
        except
            on Error: EException do
                FreeAndNil(SMTP);
                // Logging('SMTP_PrepareSMTP', Error);
                raise Error;
            end;
        end;
        procedure SMTP_PrepareEmail();
        begin
        MessageEmail:=TIdMessage.Create(nil);
        try
            MessageEmail.ContentTransferEncoding:='base64';
            MessageEmail.From.Address:=Username;
            MessageEmail.Recipients.EMailAddresses:=ToTarget;
            MessageEmail.CharSet:='UTF-8'; // 'Windows-1251';
            MessageEmail.Subject:=Subject; // AnsiToUtf8(UTF8Encode(WideString(ConvertToWIN1251(
            MessageEmail.Body.text:=Body;
        except
            on Error: EException do
                FreeAndNil(MessageEmail);
                // Logging('SMTP_PrepareEmail', Error);
                raise Error;
            end;
        end;
        procedure SMTP_PrepareAttach();
        begin
        if Length(Path)>0 then
            try
                StreamFile:=TMemoryStream.Create;
                MainForm.ExcelSS.SaveToStream(StreamFile, TdxSpreadSheetXLSFormat);
                StreamFile.Position:=0;
                AttachMemory:=TIdAttachmentMemory.Create(MessageEmail.MessageParts, StreamFile);
                try
                    AttachMemory.ContentType:='text/plain';
                    AttachMemory.FileName:=ClearFileName(StringReplace(Path, '*', 'х', [rfReplaceAll, rfIgnoreCase]), ' ');
                except
                    on Error: EException do
                        FreeAndNil(AttachMemory);
                        // Logging('SMTP_PrepareAttach', Error);
                        raise Error;
                    end;
            finally
                FreeAndNil(StreamFile);
                end;
        end;
        procedure SMTP_TryToSend();
        const MAX_ATTEMPTS_CNT = 10; WAIT_TIME = 100;
        var CurrentAttempt: Integer;
        begin
        CurrentAttempt:=0;
        while (CurrentAttempt<MAX_ATTEMPTS_CNT) do
            begin
            Inc(CurrentAttempt);
            try
                SMTP.Send(MessageEmail);
                Result:=True;
                Exit;
            except
                on Error: EIdConnClosedGracefully do
                    Sleep(WAIT_TIME);
                else
                    raise Error;
                end;
            end;
        end;
begin
Result:=False;
// Path:=Trim(Path); // ???
// if not FileExists(Path) then Path:=''; // ???
try
    SMTP_PrepareSMTP();
    try
        SMTP.Connect();
        try
            SMTP_PrepareEmail();
            try
                SMTP_PrepareAttach();
                try
                    SMTP_TryToSend();
                finally
                    if Assigned(AttachMemory) then FreeAndNil(AttachMemory);
                    end;
            finally
                FreeAndNil(MessageEmail);
                end;
        finally
            SMTP.Disconnect(False);
            end;
    finally
        FreeAndNil(SMTP);
    end;
except
    MessageDlg('Ошибка при отправки письма!'+DoubleLineBreak+'ClassName :: "'+E.ClassName+'"'+LineBreak+'Message :: "'+E.Message+'"', mtError, [mbOK], 0);
    end;
end;